Thank you for being a valued part of the CNET community. As of December 1, 2020, the forums are in read-only format. In early 2021, CNET Forums will no longer be available. We are grateful for the participation and advice you have provided to one another over the years.

Thanks,

CNET Support

Question

Binary

Sep 19, 2015 11:55AM PDT

How many different colors could be represented with an RGBO scheme if 7 bits were used to represent each RGBO component?

Discussion is locked

- Collapse -
Answer
O being Opacity is not a color.
Sep 19, 2015 12:23PM PDT

So that would give us 3x7 or 21 bits of color. 2^21 is a little over 2 million unique colors.

So with 10 million colors kicked around by human vision ( https://en.wikipedia.org/wiki/Color_vision ) you could ask if this is enough. I'm going with good enough as the color gamut ( https://en.wikipedia.org/wiki/Gamut ) of most displays don't cover the full human eye spectrum so in short, it's good enough.

- Collapse -
O being Orange
Sep 19, 2015 5:19PM PDT

In the question I had to answer, it said O was represented for Orange. Does that make a difference

- Collapse -
Re: orange
Sep 20, 2015 3:05AM PDT

Indeed, the common abbrevation, taking opacity into account is RGBA. But orange is a color that can be made from RGB (common values are 255-165-0 = fffa00 and 255-153-0 = ff9900 and probably everything in between for the green). A nice example of the last: http://www.colorcombos.com/colors/FF9900

So it's a rather strange question. Please ask your teacher for any reference for an red-green-blue-orange color scheme. I can't find it, probably because it doesn't make sense. So I think it's a bad question. But if it is a good question, it surely makes a difference, as you surely understand.

Kees

- Collapse -
Why yes it would.
Sep 20, 2015 10:00AM PDT

As I've never found an RGBO display system, then you'll have to share make, model and links for me to learn more about this system. For humans, we used RGB due to how human vision works. I can't guess why anyone created one with orange.

- Collapse -
Answer
Re: binary
Sep 19, 2015 12:33PM PDT

That's easy math, although the answer depends on if you consider 2 colors with the same RGB and different opacity the same or different. And also on if you consider 2 colors with opacity 0 and different RGB values the same.

And, alas, we don't do your homework for school. That's something you should do yourself.

To start thinking about the problem, answer the following question: How many different colors could be represented with an RGBO scheme if 1 bit was used to represent each RGBO component? That's the binary variant you're asking for in your subject line.
Check you answer on http://www.cssportal.com/css3-rgba-generator/ (use max on the slider for 1 and min for 0). Then - bonus assignment - make an html-page showing all those colors.

Kees