The colors that you are showing as appropriate for halfdrow are not appropriate, those colors belong on drow. You keep saying dusky but you don't even understand what it is, you say that half elfs cant be dusky? Again dusky is a shade not a color, so like medium dark brown would be considered dusky, someone from chult would be considered dark, a northman would be considered pale toned. If a northman and a chultan have a kid they would be dusky, aka darkish.
And also apparently you guys cant tell the difference between almost as much as and the same. You use a quote from races of faerun. That describes how others typically view them
Wow that's weird here it says they are considered second class members of drow society, and that in human society they are distrusted nearly as much as their full blooded cousins.Races of Faerun Pg 63 on Half-Drow
In most lands, half-drow are rare. Since so
many drow are irredeemably evil, they only
mate with humans by way of rape or slavery.
The only exception are the half-drow of the land of Dambrath
in the Shining South, who arise from the centuries-old drow subjugation
of the human folk of that land.
Half-drow have dusky skin, silver or white hair, and a broad
range of eye colors. They are often just as dark-hearted as their
elven parents, but with a bitter resentment that comes from
knowing that they are considered second-class members of drow
society. In human society, half-drow are distrusted nearly as
much as their full-blooded cousins. Despite this, good half-drow
are much less rare than good drow. Whether this has to do with
the influence of their human blood, or the desire to rebel against
the drow who treat them so poorly, is difficult to tell.
So in what world is nearly as much the same as identical to? You want to add a new rule and then claim its lore when its not is lying. This rule that you have makes NPC reactions the same for halfdrow as they do for drow is not lore accurate stop trying to sell it as lore accurate. Because the races of faerun book says they are not the same. If you want to have NPCs react appropriately to a race you don't need a new rule stating that its this way.