I want to draw a colored pixel by sending a message to pd.
I can use GEM, but I would prefer not using it (because I didn't use it yet, so I have not much experience).
So if someone gives me a GEM example it should be very easy to follow.
I am searching the Internet now for a week and couldn't find anything.

@tommsch Hello there,
There might well be other ways. This draws a small square, which you can colour, move, rotate and size (in Gem). It is fairly easy to understand.... and on my laptop, at a size of 0.006 it is (about) a pixel.
pixel_processing.pd
David.