Iris Classon
Iris Classon - In Love with Code

(Not so) Stupid Question 282: Why RGB and not RYB?

January 1st, and time to make those New Year’s resolutions. I’ll share one (and the rest later this week) which you might have already guessed. My ‘stupid questions’-they are back. I think I vowed to start with those again last year, but didn’t.

To be honest it is hard to ask certain questions, in particularly publicly. I know we say that there are no stupid questions, but we still do perceive many questions as stupid. And nobody likes to feel stupid. I’m torn between protecting my self-esteem or learning, risking coming to the wrong conclusion due to lack of input or risking being perceived as stupid but on the other side sourcing more answers and getting better at asking/finding information.

I nearly lost my life last year, and it’s funny how that changes your view on things. And frankly, feeling stupid is not something that bothers me that much anymore, missing out on conversations and learning does however bother me. So my stupid questions are back, and back to stay. Each with a little story, and hopefully I’ll see you all joining in with stories, theories and answers. As I’ve always said, I’d rather be the most stupid person on a team of brilliant people, than the smartest person on the team. Of course in reality you can’t really measure those things, so the ranking is all in our head.

FIY on the Stupid Question series:

[To celebrate my first year of programming I will ask a ‘stupid’ questions daily on my blog for a year, to make sure I learn at least 365 new things during my second year as a developer]

Anyway, here is todays stupid question and the backstory.

Why RGB and not RYB?

Me going RGB. With Red, Green and Blue hair. I’ve had every color in the book :) -within one year probably haha

I was explaining the primary colors to a 4-year-old and another programmer mentioned RGB. And it got me thinking. Why on earth is it that we use RGB and RYB in that color model?

Let me explain. RGB stands for Red Blue Green, and is one of many color models used to represent colors digitally. By ‘mixing’ different amounts of the three colors we can produce (almost) any color (depending on the color depth, 8, 16 or 32, the more the more colors we can produce). Back in the physical world we have the primary colors. Red Yellow Blue. If you had three tubes, one with each color, you could mix any color you wanted with them (expect white- but there begins the question if white is a color).

So why the difference?

When you mix colors you could divide the mixing in two main categories, mixing that produces lighter colors called additive color, or mixing that produces darker, subtracting color. The computer monitor is an emitting element, and hence using additive colors (where combining colors yield lighter colors as they emit light) makes sense,- and RGB color model is an additive color model. In the real world, or when printers are printing out those images the ink or paint is layered, creating darker colors the more the mix. Printers use the CMY(K) color model, Cyan, Magenta, Yellow,- similar to Red Yellow Blue if you think about it. K stands often for black ink, used to cover up mishaps and make images seem more sharp. So the difference is between missing light and mixing paint.

As I understand it anyway. So, tell me, would this be a fair reply? Or have I missed out on some info here?

Comments

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Fernando
1/1/2016 3:12:21 PM
NSSQ is back! Great! All the best for you. 
CB
1/1/2016 5:17:29 PM
I never thought about the additive vs subtractive; I learned about RGB as a theater major dealing with lighting the stage, and from RGB you can make yellow, cyan, and magenta as secondary colors, and any other shade as subtle or as strong as you like.
Also, I suspect ROYGBIV has to be part of the discussion w/r/t light....

Great to see you are back with the (Not so) Stupid Question series.

Cheers -- 
Adam
1/1/2016 11:00:15 PM
So glad that these are back!

This makes a lot of sense; especially about light-emitting science and the benefit of using additive vs. subtractive mixes.

Cheers Iris! :) 
James
1/2/2016 6:08:16 AM
That's about it- the difference between additive primary colours and subtractive. 
I've often had a discussion (um, argument) with the wife about what are the primary colours- she comes at it from an art point of view and thinks RYB, whereas I come at it from a photography viewpoint and think of it as RGB.
Your eyes have detectors in for RGB which is why monitors and those multi-colour LED's all emit the same three colours. Paint works by only reflecting the relevant colour and absorbing all others which is why if you mix two colours, you're absorbing even more colour than one, and it' subtractive. Yellow light can be made up of red and green light- so your monitor showing yellow will have loads of red and green dots illuminated. Yellow paint is absorbing all colours apart from the light that the red and green sensitive parts of your eyes pick up though, and when you then stir in blue paint (which absorbs red, and everything else apart from blue) you're left with just the green sensor in your eye detecting light.

I think :) 


Last modified on 2016-01-01

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