Calibrate Neopixels RGB lut

[yorenschriever]

The current lut is not optimal.

i think it can be improved with these steps:

• take a led ring, put 3 sections on it with 1 colour each (R,G,B), turn of lut, and play with relative intensities until you perceive them as equally bright
• for each colour individually print a gradiont on the ring. plat with the gamma value until half the brightness is at half the ring. each led shouldhave an equal step in brightness to the next one
• have a rotating rainbow on the ring. it should not look bumpy: brightness should feel equal; across RGB, but also in between (CMY)