Articles and Books:
The work of Radhika Parameswaran, in Indiana University’s Media School
Articles on Aryan and Non-Aryan in South Asia, edited by J. Bronkhors and M. Deshpande, Harvard University.
H H Hock’s “Through a glass darkly: Modern racial interpretations vs. textual analysis and general prehistoric evidence on army and dasa/dasyu in Vedic society”
T. Trautmann’s “Constructing the racial theory of Indian Civilization”
Romila Thapar’s The Theory of Aryan Race and India: History and Politics. Social Scientist vol. 24. 1/3 1996 pp.3-29.
K. Kennedy. “Have Aryans been identified in the prehistoric skeletal record from South Asia? Biological anthropology and concepts of ancient races” in The Indo-Aryans of Ancient South Asia. G. Erdosy. De Gruyter. 1995
Patrick McCartney in the Wire, including textual references to dark skin but focuses on explaining the relation between “skin whitening for yoga” and “face yoga.” https://thewire.in/culture/yoga-skin-whitening
On varna in the Mahabharata, see Wendy Doniger’s The Hindus: An Alternative History, p. 286-287.
David Kinsley’s The Sword and the Flute compares Krsna and Kali devotional traditions and has a number of references to their dark skin color. However, the gendered dimensions are complex, as Radha is often described as golden and Kali is often seen as exceptional rather than paradigmatic for gendered notions of Indian beauty. In any case, this is a good source for the compilation and translation of Sanskrit texts about Krishna and Kali.
In terms of modern lightening efforts for historically dark-skinned deities:
Kajri Jain’s Gods in the Bazaar.
Rachel McDermott’s Revelry, Rivalry, and Longing, about the worship of Durga and Kali in Bengal, has a chapter on the gradual “lightening” of representations of Kali over the past decades. (Ch 6:”The “orientalist Kālī” : a Tantric icon comes alive”)
Also, there are a range of public culture resources on the centrality of skin color in Indian society:
Zinnia Ray Chaudhuri, Dark is Divine: A photographer uses his camera to challenge India’s obsession with fairness, at Scroll.in (linked here)
A article profiling Nandita Das’s ‘India’s Got Colour’ campaign (linked here)
RV 5.77.03 discusses the golden-skinned, honey-coloured, ghee-backed…
hiraṇyatvaṅ madhuvarṇo ghṛtasnuḥ pṛkṣo vahann ā ratho vartate vām |
manojavā aśvinā vātaraṁhā yenātiyātho duritāni viśvā || RV_5,077.03
See kṛṣṇā-tvac (“black skin”) (Ṛgveda 1.130.08)
indraḥ samatsu yajamānam āryam prāvad viśveṣu śatamūtir ājiṣu svarmīḻheṣv ājiṣu |
manave śāsad avratān tvacaṁ kṛṣṇām arandhayat |
dakṣan na viśvaṁ tatṛṣāṇam oṣati ny arśasānam oṣati || RV_1,130.08