Gray Scale
The Gray Scale color selection option can be used to alter the brightness and opaqueness (opposite of transparency) of a color. To access this option, press on the Color Selection Menu and then tap on Gray Scale.
To change the values, press on a slider and then move your finger to the right or left to set the desired color value. You may also tap on the number to type in a different value.
Tap on the Hex Editor to alter the color by changing the value or use the Favorites Button to save it to the list of favorite colors.