Zerdly

Light Mixer

An additive-colour puzzle. Three lights — red, green and blue — fade with distance. Where they overlap, their light adds up. Arrange them so each sensor reads exactly its target.

Move a red, a green and a blue light and set their brightness until every sensor reads its target colour.

FreeOn this device

1RGB
Red light
Green light
Blue light

Sensors

  • Sensor 1 at (6, 4): not yet — now black, target red

    Red0.00 / 1.00
    Green0.00 / 0.00
    Blue0.00 / 0.00

Values are linear game colours, matched channel by channel — not a model of real lamps or paints, and not a perceptual colour-difference score. Many layouts can work.

0 of 1 sensors matched (each channel within 0.03).

Controls

  • Drag a light around the stage, or type its x and y position.
  • Set each light's brightness with its slider.
  • Each sensor lists its red, green and blue readings against the target, with a bar and a marker for each channel. Reset lights puts them back.

The rules

  • A light adds to its own channel only: full brightness at its centre, fading evenly to nothing 4 units away.
  • Channels add where lights overlap and can't go above 1 — red plus green reads as yellow.
  • A sensor is matched when every channel is within 0.03 of its target. Solve the puzzle by matching all of them; any arrangement that does so counts.

Scoring, saving and limits

Solved or not — there is no point score. Each channel's difference is shown separately.

Your light positions and solved puzzles are kept on this device only. Download a backup to move them.

Game colours computed in linear RGB and shown in sRGB. They don't simulate real lamps or pigments, and the match is per channel, not a perceptual colour-difference measure.

Questions

Why does red plus green make yellow?
Screens and lights mix additively: adding red and green light gives yellow, and all three at full strength give white.
I can't tell the colours apart — can I still play?
Yes. Every sensor shows each channel as a number and a bar with its target marked, and names the colour in words.
Is there only one solution?
Often not. Any arrangement that brings every sensor within tolerance is accepted.