system
Given the following post, respond as if you're commenting on Reddit:
human
How to make orange light from a red LED?

I want to know what colour filter I need to put over a red LED to make it appear orange.

I was thinking yellow, but I know that optics is different to paints :P

Thanks!!
gpt
Although not perfect like a laboratory laser or anything, red LED's pretty much just pour out red light only. Therefore putting any filter over it (other than red) will just result in darkness, or a VERY VERY dim orange light from the 1% or whatever of the original output that was orange getting through.

There could be exotic ways to get orange from a red LED, such as finding some sort of fluorescent material that will absorb multiple photons of red and the fluoresce a smaller number of orange back out. Although most fluorescence (like an orange highlighter) tends to go from higher energy to lower energy which would be in the wrong direction for you.

Regardless, all of that would be immensely more expensive and time consuming than just buying an orange LED.