to black. I'm using "Change to Color" and using eyedropper click on mask of the car but it does almost nothing. I've tried various points on mask and it still didn't color car to black. I think it's cause may be that white is mixture of all the colors. But still there shouldn't be way to replace white. How to do it?
I've never used that plug, but generally speaking, it sounds similar to the difference between the "hue" and "color" overlay modes.
If you apply a layer style to it, for instance (Layer/Layer Styles) with a color overlay, then choose the color you want in the color picker, you'll notice if you set the overlay mode to "hue", it will only change the color but leave the saturation intact. If you change to "color", it will add more specific color even though the saturation may have been very low (gray, white, etc)
You'll notice the same thing if you use the hue and saturation effect. The hue alone won't be changing it, but if you check the "colorize" box, you'll start to see it narrowing in on the chosen hue vs the full broad spectrum light (white).