The four yuga-avataras are...

Expressions researched:
"Age of Kali, Lord Krsna assumes a golden color" |"As the white incarnation" |"Dvapara-yuga, the complexion is black, Krsna" |"Hayagriva in the Satya-yuga" |"In Dvapara-yuga the Supreme Personality of Godhead appears with a dark blue complexion" |"In Satya-yuga the Lord appeared" |"In Treta-yuga the Lord appears with a red complexion" |"In Treta-yuga, the Lord appeared" |"Kali-yuga, the complexion is yellow. Lord Caitanya" |"Kapiladeva" |"Lord Krsna personally appeared as Lord Caitanya Mahaprabhu" |"Lord Krsna, appearing in a blackish body" |"Satya-yuga the Lord is white" |"Treta-yuga, the complexion is red" |"in Kali-yuga, Bhagavan has appeared in pita-varna, or a yellow color, as Gaurasundara" |"pita (yellow) as Caitanya Mahaprabhu in Kali-yuga" |"rakta (red) in Treta-yuga" |"reddish incarnation" |"sukla (white) in Satya-yuga" |"syama (dark blue) in Dvapara-yuga" |"the Lord incarnates in four colors" |"the Personality of Godhead appears in a blackish hue" |"the prescribed color for different millenniums" |"yuga-avataras"

SB Canto 10.1 to 10.13

SB 10.8.13, Translation and Purport:

Your son Kṛṣṇa appears as an incarnation in every millennium. In the past, He assumed three different colors—white, red and yellow—and now He has appeared in a blackish color. (In another Dvāpara-yuga, He appeared (as Lord Rāmacandra) in the color of śuka, a parrot.) All such incarnations have now assembled in Kṛṣṇa.

Partially explaining the position of Lord Kṛṣṇa and partially covering the facts, Gargamuni indicated, "Your son is a great personality, and He can change the color of His body in different ages." The word gṛhṇataḥ indicates that Kṛṣṇa is free to make His choice. In other words, He is the Supreme Personality of Godhead and may therefore do whatever He desires. In Vedic literature the different colors assumed by the Personality of Godhead in different millenniums are stated, and therefore when Gargamuni said, "Your son has assumed these colors," he indirectly said, "He is the Supreme Personality of Godhead." Because of Kaṁsa's atrocities, Gargamuni tried to avoid disclosing this fact, but he indirectly informed Nanda Mahārāja that Kṛṣṇa, his son, was the Supreme Personality of Godhead.

It may be noted that Śrīla Jīva Gosvāmī, in his book Krama-sandarbha, has enunciated the purport of this verse. In every millennium, Kṛṣṇa appears in a different form, either as white, red or yellow, but this time He personally appeared in His original, blackish form and, as predicted by Gargamuni, exhibited the power of Nārāyaṇa. Because in this form the Supreme Personality of Godhead exhibits Himself fully, His name is Śrī Kṛṣṇa, the all-attractive.

Factually, Kṛṣṇa is the source of all avatāras, and therefore all the different features of the different avatāras are present in Kṛṣṇa. When Kṛṣṇa incarnates, all the features of other incarnations are already present within Him. Other incarnations are partial representations of Kṛṣṇa, who is the full-fledged incarnation of the Supreme Being. It is to be understood that the Supreme Being, whether appearing as śukla, rakta or pīta (white, red or yellow), is the same person. When He appears in different incarnations, He appears in different colors, just like the sunshine, which contains seven colors. Sometimes the colors of sunshine are represented separately; otherwise the sunshine is observed mainly as bright light. The different avatāras, such as the manvantara-avatāras, līlā-avatāras and daśa-avatāras, are all included in the kṛṣṇa-avatāra. When Kṛṣṇa appears, all the avatāras appear with Him. As described in Śrīmad-Bhāgavatam (SB 1.3.26):

avatārā hy asaṅkhyeyā

hareḥ sattva-nidher dvijāḥ

yathāvidāsinaḥ kulyāḥ

sarasaḥ syuḥ sahasraśaḥ

The avatāras incessantly appear, like incessantly flowing water. No one can count how many waves there are in flowing water, and similarly there is no limitation of the avatāras. And Kṛṣṇa is the full representation of all avatāras because He is the source of all avatāras. Kṛṣṇa is aṁśī, whereas others are aṁśa, part of Kṛṣṇa. All living entities, including us, are aṁśas (mamaivāṁśo jīva-loke jīva-bhūtaḥ sanātanaḥ (BG 15.7)). These aṁśas are of different magnitude. Human beings (who are minute aṁśas) and the demigods, viṣṇu-tattva and all other living beings are all part of the Supreme. Nityo nityānāṁ cetanaś cetanānām (Kaṭha Upaniṣad 2.2.13). Kṛṣṇa is the full representation of all living entities, and when Kṛṣṇa is present, all avatāras are included in Him.

The Eleventh Canto of Śrīmad-Bhāgavatam describes the incarnations for each yuga in chronological order. The Bhāgavatam says, kṛte śuklaś catur-bāhuḥ, tretāyāṁ rakta-varṇo'sau, dvāpare bhagavān śyāmaḥ and kṛṣṇa-varṇaṁ tviṣākṛṣṇam (SB 11.5.32). We actually see that in Kali-yuga, Bhagavān has appeared in pīta-varṇa, or a yellow color, as Gaurasundara, although the Bhāgavatam speaks of kṛṣṇa-varṇam. To adjust all these statements, one should understand that although in some yugas some of the colors are prominent, in every yuga, whenever Kṛṣṇa appears, all the colors are present. Kṛṣṇa-varṇaṁ tviṣākṛṣṇam: although Caitanya Mahāprabhu appears without kṛṣṇa, or a blackish color, He is understood to be Kṛṣṇa Himself. Idānīṁ kṛṣṇatāṁ gataḥ. The same original Kṛṣṇa who appears in different varṇas has now appeared. The word āsan indicates that He is always present. Whenever the Supreme Personality of Godhead appears in His full feature, He is understood to be kṛṣṇa-varṇam, although He appears in different colors. Prahlāda Mahārāja states that Caitanya Mahāprabhu is channa; that is, although He is Kṛṣṇa, He is covered by a yellow color. Thus the Gauḍīya Vaiṣṇavas accept the conclusion that although Caitanya Mahāprabhu appeared in pīta color, He is Kṛṣṇa.

kṛṣṇa-varṇaṁ tviṣākṛṣṇaṁ

sāṅgopāṅgāstra-pārṣadam

yajñaiḥ saṅkīrtana-prāyair

yajanti hi sumedhasaḥ

(SB 11.5.32)

SB Cantos 10.14 to 12 (Translations Only)

SB 11.5.21, Translation:

In Satya-yuga the Lord is white and four-armed, has matted locks and wears a garment of tree bark. He carries a black deerskin, a sacred thread, prayer beads and the rod and waterpot of a brahmacārī.

SB 11.5.23, Translation:

In Satya-yuga the Lord is glorified by the names Haṁsa, Suparṇa, Vaikuṇṭha, Dharma, Yogeśvara, Amala, Īśvara, Puruṣa, Avyakta and Paramātmā.

SB 11.5.24, Translation:

In Tretā-yuga the Lord appears with a red complexion. He has four arms, golden hair, and wears a triple belt representing initiation into each of the three Vedas. Embodying the knowledge of worship by sacrificial performance, which is contained in the Ṛg, Sāma and Yajur Vedas, His symbols are the ladle, spoon and other implements of sacrifice.

SB 11.5.26, Translation:

In Tretā-yuga the Lord is glorified by the names Viṣṇu, Yajña, Pṛśnigarbha, Sarvadeva, Urukrama, Vṛṣākapi, Jayanta and Urugāya.

SB 11.5.27, Translation:

In Dvāpara-yuga the Supreme Personality of Godhead appears with a dark blue complexion, wearing yellow garments. The Lord's transcendental body is marked in this incarnation with Śrīvatsa and other distinctive ornaments, and He manifests His personal weapons.

SB 11.5.32, Translation:

In the age of Kali, intelligent persons perform congregational chanting to worship the incarnation of Godhead who constantly sings the names of Kṛṣṇa. Although His complexion is not blackish, He is Kṛṣṇa Himself. He is accompanied by His associates, servants, weapons and confidential companions.

CC Madhya-lila

The four yuga-avatāras are:

CC Madhya 20.246, Purport:

The four yuga-avatāras are (1) śukla (white) in Satya-yuga (SB 11.5.21), (2) rakta (red) in Tretā-yuga (SB 11.5.24), (3) śyāma (dark blue) in Dvāpara-yuga (SB 11.5.27) and (4) generally kṛṣṇa (black) but in special cases pīta (yellow) as Caitanya Mahāprabhu in Kali-yuga (SB 11.5.32) and (SB 10.8.13)

CC Madhya 20.329, Translation:

“O Sanātana, now hear from Me about the yuga-avatāras, the incarnations for the millenniums. First of all, there are four yugas—Satya-yuga, Tretā-yuga, Dvāpara-yuga and Kali-yuga.

CC Madhya 20.330, Translation:

“In the four yugas—Satya, Tretā, Dvāpara and Kali—the Lord incarnates in four colors: white, red, black and yellow respectively. These are the colors of the incarnations in different millenniums.

CC Madhya 20.331, Translation and Purport:

“"This child formerly had three colors according to the prescribed color for different millenniums. Formerly He was white, red and yellow, and now He has assumed a blackish color."

This verse from Śrīmad-Bhāgavatam (SB 10.8.13) was spoken by Garga Muni when performing the name-giving ceremony for Kṛṣṇa at the house of Nanda Mahārāja. The following two verses are also from Śrīmad-Bhāgavatam (SB 11.5.21, 24).

CC Madhya 20.332, Translation:

“"In Satya-yuga the Lord appeared in a body colored white, with four arms and matted hair. He wore tree bark and bore a black antelope skin. He wore a sacred thread and a garland of rudrākṣa beads. He carried a rod and a waterpot, and He was a brahmacārī."

CC Madhya 20.333, Translation:

“"In Tretā-yuga, the Lord appeared in a body that had a reddish hue and four arms. There were three distinctive lines on His abdomen, and His hair was golden. His form manifested the Vedic knowledge, and He bore the symbols of a sacrificial spoon, ladle and so on."

CC Madhya 20.334, Translation and Purport:

“As the white incarnation, the Lord taught religion and meditation. He offered benedictions to Kardama Muni, and in this way He showed His causeless mercy.

Kardama Muni was one of the prajāpatis. He married Devahūti, the daughter of Manu, and their son was Kapiladeva. The Supreme Lord was very pleased with Kardama Muni's austerities, and He appeared before Kardama Muni in a whitish body. This happened in the Satya-yuga millennium, when people were accustomed to practicing meditation.

CC Madhya 20.335, Translation:

“In Satya-yuga the people were generally advanced in spiritual knowledge and could meditate upon Kṛṣṇa very easily. The people's occupational duty in Tretā-yuga was to perform great sacrifices. This was induced by the Personality of Godhead in His reddish incarnation.

CC Madhya 20.336, Translation:

“In Dvāpara-yuga the people's occupational duty was to worship the lotus feet of Kṛṣṇa. Therefore Lord Kṛṣṇa, appearing in a blackish body, personally induced people to worship Him.

CC Madhya 20.337, Translation and Purport:

“"In Dvāpara-yuga the Personality of Godhead appears in a blackish hue. He is dressed in yellow, He holds His own weapons, and He is decorated with the Kaustubha jewel and the mark of Śrīvatsa. That is how His symptoms are described."

This is a quotation from Śrīmad-Bhāgavatam (SB 11.5.27). The śyāma color is not exactly blackish. Śrīla Bhaktisiddhānta Sarasvatī Ṭhākura compares it to the color of the atasī flower. It is not that Lord Kṛṣṇa Himself appears in a blackish color in all the Dvāpara-yugas. In other Dvāpara-yugas, previous to Lord Kṛṣṇa's appearance, the Supreme Lord appeared in a greenish body by His own personal expansion. This is mentioned in the Viṣṇu Purāṇa, Hari-vaṁśa and Mahābhārata.

CC Madhya 20.339, Translation and Purport:

“By this mantra, the people worship Lord Kṛṣṇa in Dvāpara-yuga. In Kali-yuga the occupational duty of the people is to chant congregationally the holy name of Kṛṣṇa.

As stated in Śrīmad-Bhāgavatam (SB 12.3.51):

kaler doṣa-nidhe rājann asti hy eko mahān guṇaḥ

kīrtanād eva kṛṣṇasya mukta-bandhaḥ paraṁ vrajet

"My dear King, although Kali-yuga is full of faults, there is still one good quality about this age. It is that simply by chanting the Hare Kṛṣṇa mahā-mantra, one can become free from material bondage and be promoted to the transcendental kingdom." Thus in Kali-yuga one worships Lord Kṛṣṇa by chanting Hare Kṛṣṇa, Hare Kṛṣṇa, Kṛṣṇa Kṛṣṇa, Hare Hare/ Hare Rāma, Hare Rāma, Rāma Rāma, Hare Hare. To propagate this movement, Lord Kṛṣṇa personally appeared as Lord Caitanya Mahāprabhu. That is described in the following verse.

CC Madhya 20.340, Translation:

“In the Age of Kali, Lord Kṛṣṇa assumes a golden color and, accompanied by His personal devotees, introduces hari-nāma-saṅkīrtana, the chanting of the Hare Kṛṣṇa mantra. By this process He delivers love for Kṛṣṇa to the general populace.

Sri Caitanya-caritamrta Lectures

Lecture on CC Madhya-lila 20.330-335 -- New York, December 23, 1966:

Yugāvatāra means just like there are four yugas: Satya, Tretā, Dvāpara, Kali. The ages of each yuga we have mentioned already. Now in the Satya-yuga, when the yugāvatāra comes, He is white. He is Hayagrīva in the Satya-yuga, as white as our Hayagrīva brahmacārī. Yes. He is white. And rakta. Śukla-rakta-kṛṣṇa-pīta-krame cāri varṇa. In the Satya-yuga when the incarnation of yugāvatāra comes, His complexion is white. And in the next yuga, Tretā-yuga, the complexion is red. And the next yuga, Dvāpara-yuga, the complexion is black, Kṛṣṇa. And the next, Kali-yuga, the complexion is yellow. Lord Caitanya is yellow.