flexi-bot/docs/marlin/_gcode/M150.md

tag	title	brief	author	requires	group	codes	notes	parameters	examples
m0150	Set RGB(W) Color	Set the color of the RGB(W) LED, backlight, or LED strip.	thinkyhead	BLINKM|RGB_LED|RGBW_LED|NEOPIXEL_LED|PCA9632	lcd	M150	Requires `BLINKM`, `RGB_LED`, `RGBW_LED`, `NEOPIXEL_LED` or `PCA9632`.	tag optional description values R true Red component from 0 to 255 tag type intensity byte tag optional description values U true Green component from 0 to 255 tag type intensity byte tag optional description values B true Blue component from 0 to 255 tag type intensity byte tag optional description values W true White component from 0 to 255 (`RGBW_LED` or `NEOPIXEL_LED` only) tag type intensity byte tag optional requires description values P true NEOPIXEL_LED Brightness from 0 to 255 (Requires `NEOPIXEL_LED`) tag type intensity byte tag since optional requires description values I 2.0.6 true NEOPIXEL_LED NeoPixel pixel index (0 .. pixels-1) (Requires `NEOPIXEL_LED`) tag type pixel int tag since optional requires description values S 2.0.6.1 true NEOPIXEL2_SEPARATE NeoPixel strip index (0 or 1) (Requires `NEOPIXEL2_SEPARATE`) tag type strip int tag optional requires description values K true NEOPIXEL_LED Keep all unspecified values unchanged (Requires `NEOPIXEL_LED`) type flag	pre code Set LEDs to blue with brightness 30 M150 B30 pre code Set NeoPixel 0 to red with brightness 100 M150 R100 I0 pre code Set NeoPixel 1 to green with brightness 45 M150 U45 I1 pre code Set the second NeoPixel strip full white M150 W255 S1 pre code Change red to 50% without changing other components M150 K R127

If you have an RGB(W) light, either as part of a controller or installed separately, the M150 command can be used to set its color.