Im always confused by RGB. I learned that if you want orange, you mix red and yellow. If you want green, you mix blue and yellow, if you want purple, you mix red and blue.
How is it that computers need green and not yellow?
Computer screens emit light, so when your computer shows a green LED next to a red LED, both green and red light wavelengths are sent to your eyes, and your brain interprets this as yellow. This is because your eyes only have red, green, and blue receptors in them, so sending green light mixed with red light is indistinguishable from pure yellow light.
Pigment, instead, works by absorbing light. The trick is that red, yellow, and blue are not the primary colors of light–it’s instead Cyan, Magenta, and Yellow (which look similar to Red, Yellow, and Blue). Yellow pigment absorbs blue light, magenta pigment absorbs green light, and cyan pigment absorbs red light. Therefore, if you mix yellow and cyan pigments together, the resulting mixture absorbs the blue AND red light, so green is the only wavelength left that gets reflected back and picked up by your eyes.
I found a video on it that explained this well with a neat diagram: https://youtu.be/YtH9eXWuf3Y?t=44
It’s just the concept of additive color mixing vs subtractive color mixing.
Adding pigments together will ultimately create black. While adding more light together will ultimately make white.
With pigments you’re taking away from the color space. You paint red to subdue all other colors except for red.
But you use red light to make sure red is better seen.
It’s kinda cool (to me at least lol) how literal the terms “additive” and “subtractive” for color mixing are. With additive mixing (such as on a computer screen), you start with black and add the primary colors (RGB) in different combinations. If you add all of them you get white.
Subtractive mixing (like pigments) starts from white and “subtracts” those same RGB colors. You can think of cyan, magenta, and yellow as “minus red”, “minus green”, and “minus blue” respectively, since that’s which wavelengths thise pigments absorb. So mixing cyan and magenta for instance gives you “white (RGB) minus red minus green”, which leaves only blue.
Also how did the “o” from the word “color” in my title make its way to the end of the sentence? 😂
You moved an image in Microsoft word 3 years ago.
If you want to fix it, there should be an edit button behind the 3 dot menu under your post heading which will allow you to put that ‘o’ back where it belongs.
Technology Connections has a couple interesting videos on the subject. Here’s one focused on the color brown with an explanation of additive vs. subtractive color (mixing light vs. pigments) starting around this timestamp. There’s also this video with some cool demonstrations using RGB LEDs and some common household objects.
