Valmiki always makes detailed descriptions. But we seem to overlook due to preconceived notions. One such is while using similes about both Vali and Sugriva he uses Black clouds. If they are the Rhesus type then the colour black does not fit them. Lets us see. In 4-12-16 while describing Vali he uses the word(तोयदः)which refer to Black water bearing cloud. If Vali is Gorilla then Sugriva who is almost his twin also should be Gorilla. In the same sarga in sloka 4-12-41 Sugriva is also compared to same (तोयदः). If not convincing see 4-17-6 (पयोधर) again meaning black water bearing cloud for comparing Vali. And again in 4-19-22 (महामेघ औघ निःस्वनम्).
For those who are still unconvinced and again when Sugriva calls all the monkeys in 4-37-20 he says 30 Million fly jumpers (monkeys) whose shine is like black mascara (अंजन संकाशा) so the colour is black.
Also the word Vanara in Sanskrit means Semi human. Now the clincher. Valmiki takes great pleasure in expressing emotions using tail for Hanuman or many of the monkeys. In Sundara kanda (23 slokas) and Yudha Kanda (13 slokas) there are mentioning tails of the monkeys. But in Kishkinda Kanda there is absolutely no mention of tail though emotions of valour pathos anger etc. run very high. Why? Because both Vali and Sugriva do not have tail. So…..?
List of Slokas
तम् श्रुत्वा निनदम् भ्रातुः क्रुद्धो वाली महाबलः |
निष्पपात सुसंरब्धो भास्करो अस्त तटात् इव ||
|On hearing his brother’s shouting that great mighty Vali is infuriated and impetuously rushed out of his palace chambers, like the sun falling back onto sky from his dusking brink. Back|
स तथा शुशुभे श्रीमान् लतया कण्ठ सक्तया |
मालया इव बलाकानाम् ससंध्य इव तोयदः ||
|He that prosperous Sugreeva with that flowery-creeper adorning his neck then shone forth like a black rain cloud against a backdrop of rich ochry colour of sunset, and with a train of herons adorning that cloud like a garland. Back|
स तया मालया वीरो हैमया हरियूथपः |
संध्यानुगत पर्यन्तः पयोधर इव अभवत् ||
|By still wearing that golden chest-pendant around his neck, that brave general of monkeys Vali appeared like a black-cloud smeared with the colour of golden sunset all around its edges. Back|
क्षेप्तारम् पर्वत इन्द्राणाम् वज्राणाम् इव वासवम् |
महावात समाविष्टम् महामेघ औघ निःस्वनम् ||
|She saw Vali who is a flinger of loftiest mountains as with Indra flinging his thunderbolt, who is a blaster as with great gusty winds, and who is a roarer as with a cluster of great black-clouds. Back|
ततः ते अंजन संकाशा गिरेः तस्मात् महाजवाः |
तिस्रः कोट्यः प्लवंगानाम् निर्ययुर् यत्र राघवः ||
|Then thirty million fly-jumpers whose swiftness is inconceivable, and whose shine is like that of black-mascara have sallied forth from mountain Anjana to there where Raghava is camping, i.e., Mt. Prasravana. Back|
All Sloka Translations are from the site Valmiki Ramayana