color white.
Draw with a white crayon by touching the rainbow color slider and dragging your finger to the top-left corner. Android users already have the white crayon built into their rainbow slider.
Draw in the color black.
Similarly, you can draw with a black crayon by touching the rainbow color slider and dragging your finger to the bottom. Android users already have the black crayon built into their rainbow slider.
Draw in hidden colors.
You’ll notice when you drag your finger from the rainbow slider to the left or to the bottom of the snap, you’ll be able to use a bunch of in-between colors that aren't available on the palette.
Draw with a transparent color (only on Android devices).
If you have an Android device, you're in luck. Snapchatters using Androids can draw with a see-through color. Press down on the rainbow slider until the full color palette appears, and then select the transparent color.