With a combination of one and two finger swipes you can quickly see any color the device is capable of displaying.

Some features:

• Single finger swipe controls Hue (horizontal) and Saturation (vertical)
• Double finger swipe controls Hue (horizontal) and Brightness (vertical)
• Triple finger swipe up & down to control the display brightness
• Double tap the screen or tap the "?" in the lower right corner to see the info screen
• Tap the lock icon in the upper right to lock the screen so finger swipes don't change the color.