The Compendium of Bheḷa 4.8.3

4.8.3

sā cedevamākāṅkṣetaudvāhike[evayā kāṃkṣā-] śivāvadātaputraṃjanayeyam[janayanti] iti, yavānāṃ manthaṃ[mandaṃ] sarpissamyuktaṃ saptarātramanupahataṃ bhuñjīta | tatodauhṛdinī[dauhṛtdvi] śvetāyā goḥ sarūpavatsāyāḥ payasi pāyasaṃ pācayitvātadevāśnīyāt [-atmīyāt] | śukle ca vāsasīparidadhyāt [parirabhyāt] | sarvaśvetaṃ cāsyāḥ saṃskṛtaṃ vimānaṃ kārayet | vṛṣabhamaśvaṃ[vṛṣabhagaga] vāsyā darśayet | evamavadātaṃ putraṃ janayet | netyāha śaunakaḥ | paiṅgalyaṃ vā tato ' pyatreti | ātreya uvāca kiṃ syādāvādhakam, piṅgalāvayavayā āyuṣmanto nīrogāś ca bhavantīti ||

If at the time of marriage she should desire, "May I give birth to an auspicious, fair-complexioned son," she should consume an uncorrupted drink of roasted barley flour mixed with ghee for seven nights. / Then, experiencing pregnancy cravings, she should cook milk-rice in the milk of a white cow with a calf of identical color, and eat only that. / She should wear white garments; / one should have an adorned pavilion made for her entirely in white; / and one should show her a white bull or horse. / Thus she will give birth to a fair-complexioned son. / "No," said Śaunaka, "for yellowish-brownness may result from that." / Ātreya said: "What obstacle could there be? Those with yellowish-brown limbs are long-lived and free from disease."