@praysh Bravo!
Since you have welcomed feedback on your footnote, I dared to post what I feel

The lyricist MBB Shah has indeed selected beautiful words while writing this song. Nonetheless, you have justified your nick with a well attempt (prayash). I also have this hobby....of translating lyrics/poems from Nepali-English and vice versa .  Thinking that it's one of your fav things as well, let me share a tip (but not rule) about translating . The common tendency of translators(esp. beginners)  , whethe the translation is for poem, story, essay or anything, is to do so "word" by "word", which is not the way. I realized this when you left the word "Bhadau" as it is. When you translate a literary piece, chiefly poem and songs, you need to pay attention that the "bhabh"  (theme or gist) should be kept intact rather than direct meaning. 'Cause poem is an art , not mathematics that X+X=2X is necessary. And another important thing is after you translate the poem in a regional language into a common one, the people all ver the world who know the language can share it.
 " I want shades of your hair as dark as Bhadau's rainclouds"
And I won’t need anything else "
can be paraphrased as :
" Only ifI could
be the shadows of
Those dark long hair
alike black rainclouds of July
it would suffice "

I have given two links - one contains the poems in original language by Bhupi Sherchan and the other which has them translated. Very helful for ppl having hobby like yours
http://xnepali.com/main/content/english-translation-poems-bhupi-sherchan
http://sanjaal.com/nepalipoems/5/poem-bhupi-sherchan/bhupi-sherchan-ghumne-mech-mathi-andho-manchhe/

Well this is solely my opinion and I am not a professional. Just told you what I feel. But don't forget "sunna sau ka, karna mann ka  " But I loved the starting lines. All in all, good work dude

Keep it up !