Saturday, October 8, 2011

RGB Color Wheel

I was at Irvine Sketch Jam yesterday, and I was talking to my friend Sherwin about using RGB sliders in Photoshop. He was teaching some things that really helped me understand how to properly use RGB. Thanks man.

1) First of all... primary RBG colors are Red, Green and Blue.
2) Complementary colors are different also! If you look across from the RBB color wheel, the opposite color of red is cyan, Green is Magenta, and Blue is Yellow. To get yellow, you need to have a complete absence of blue light. 
This color wheel above took me a lot of time to get right. I didn't eyeball the colors, I had the sliders mathematically correct on what each of the numbers should be. It was really tricky to shift the values of the colors while keeping the value exactly the same. I did some research on RGB color wheels, and I found this online ( . It's a great resource - even though you should do some preliminarily work before you can understand what it's saying.

Numbers for Colors
Red: 255, 0, 0
Green: 0, 255, 0
Blue: 0, 0, 255

Cyan: 0, 255, 255
Magenta: 255, 0, 255
Yellow: 255, 255, 0

Orange: 255, 128, 0
Yellow-Green: 128, 255, 0
Green-Cyan: 0, 255, 128
Blue- Cyan: 0, 128, 255
Blue-Magenta: 128, 0, 255
Red-Magenta: 255, 0, 128

Controlling Values
This is tricky. Changing values on primary/ secondary colors is slightly different from changing the value on a tertiary color. The max on a color channel is 255, and the minimum is 0. There is no negative.

For a primary and secondary colors, increase the slider by 50 points raise the value by around 10%. This is pretty exact. Red is 255, 0, 0. To make Red lighter, add 50 points (255, 50, 50). To make it darker, subtract 50 points  (205, 0, 0).

For tertiary colors, the principle applies, but the added lights need to be proportionate.
Orange is 255, 128, 0. To make it lighter, raise the Blue channel by 50 points, BUT raise the Green channel by ONLY 25 points.  This is different since the Green channel is around at 128, you need increase it by a smaller amount so the ratio of Red, Green and Blue light stays the same.

So I'm just figuring this RGB thing about.  If anything is incorrect, I apologize in advance - feel free to let me know about any inaccuracies. Thanks!

1 comment:

  1. oh dude, i was gonna go last night. next time you gonna show me all what you've just explain here. heehee :D