color property

If set, the button is filled with a solid background color and the font color changes to maintain contrast with the background color.

For example, setting a blue background likely results in white text. If unset, the image background is white and the font color is blue. For red, green, and blue, the value of each field is a float number that you can express in either of two ways: as a number between 0 and 255 divided by 255 (153/255), or as a value between 0 and 1 (0.6). 0 represents the absence of a color and 1 or 255/255 represent the full presence of that color on the RGB scale. Optionally set alpha, which sets a level of transparency using this equation: pixel color = alpha * (this color) + (1.0 - alpha) * (background color) For alpha, a value of 1 corresponds with a solid color, and a value of 0 corresponds with a completely transparent color. For example, the following color represents a half transparent red: "color": { "red": 1, "green": 0, "blue": 0, "alpha": 0.5 }