For example, I pasted an image of a splatter into VS and had image capture trace it. I set the number of colors to 2 total because the image is a white background with a solid black splatter - so white and black colors.

The result came back incorrectly as all white results. I believe what happened was the image capture detected a secondary white and so it registered two different shades of white instead of the more obvious black and white in the image.
I had then set the number of colors to 3, then tried 4 colors to get it to recognize the black.
In the images below, I set the artboard color itself to blue to help show clearly what was happening with the black and white image and the result:

here is the original file:splatter image trace test.vstyler