The background for Nyx, must be a 1280 x 720 32-bit BMP. Alpha blending is taken into account. For that reason, if a solid background is required, that value must be 0xFF. There are sites that can produce the correct bmp.
The icons supported are 192 x 192 32-bit BMP. You can utilize transparency at will and make nice mixes with the button background.
Additionally, using the `icon={sd path}`, the icon will get colorized if the name ends in `_hue.bmp`. That only works nicely if the icon is a white layout with transparency.
The default system icons (`icon_switch.bmp` and `icon_payload.bmp`) can be replaced with white layouts that have transparency. They can also be replaced with normal icons if the following exist: `icon_switch_custom.bmp` or/and `icon_payload_custom.bmp`
