Yes, good question Ric
In the past, the issue of white has been a matter of debate.
Now, if in a marble the base is white and contains two colors, it is NOT tricolor but two colors
, while, if the base of the marble has another color than white, white in addition to other colors, does it count as color ok?
So, in my opinion, white in conquerors (fancy and exsotic) counts as a color, especially if it contains little.