Re: I can see where this will lead
"Plenty of black/dark androids in Star Wars"
already done in "Rogue One", and THAT (reprogrammed imperial) 'droid was a total hero!
As for the "research" that suggests racist/sexist/name-your-bigotry behavior towards 'droids, I call B.S. on most of it. Without actually seeing the droids or how they interact with humans, I'd STILL say that "uncanny valley" is a BIG part of how people respond to them.
There is a somewhat natural aversion towards people who are different, a result of thousands of years of genetic predisposition that most likely caused races to form in the first place (and many millenia ago, was PROBABLY a survival mechanism favored by natural selection). Nowadays, people are generally taught to overlook this predisposition for obvious reasons. However, this predisposition ALSO results in the 'uncanny valley' effect when deailng with 'droids, particularly when the 'droid is close to human, but not quite.
I suggest that if the racial makeup of the bots is equal (3 droids, 3 different races), the racial makeup of the survey should ALSO be equally representative of the 3 droids. This is for the basic reason behind the 'uncanny valley' effect, that "being different" is behind the attitude people will have towards a droid of a given racial appearance.
If the droid is extremely human-like, enough to get past the uncanny valley effect, it shouldn't matter at all what race the robot appears to be. HOWEVER, if the droid is falling into the uncanny valley, AND appears to have a different race, genetic disposition may 'kick in' and cause humans to react MORE negatively towards bots that appear to be of a different race, especially if the racial features are 'hard' rather than 'soft'.
So a more 'African looking' black female 'droid would be more likely to trigger this with white or oriental people, as opposed to a 'droid that looked like Condoleeza Rice or Michelle Obama, not because of "being black" but "being different enough" in combination with the already-present 'uncanny valley' features.
Someone should've done a few more studies on this, 'droids in general, etc. Give it a green face with purple hair, oversized ears, and thin lips, and see how THAT goes (still human-looking, but different enough to push it into the uncanny valley).