No opacity slider in Mac OS X version?

[missingfoot]

Hi, the screenshot shows the opacity slider, however I'm not seeing that myself, am I missing something or has that been removed? I assume it would be possible if it were there, to generate rgba values?

Thanks!

[designbyadrian]

I too have this question! Is it because I'm highlighting a hex-code? Or using Mavericks?

[jonathanhirz]

+1, not seeing opacity on Mavericks

[jonathanhirz]

Has anyone solved this? I don't have an opacity slider on any of my color picker dialogs, even from other applications. Kind of annoying and I can't find a way to get it back.

[pri-mo]

Same here ST3 on OS X 10.10.3

[noelforte]

I also have this issue. Any news when this might be resolved?

[habovh]

The answer

Opacity cannot be included in hex codes. It must be handled differently depending on what you are doing.

You must understand that Hexadecimal color codes only contain 3 values (R, G, B) encoded in hexadecimal from 00 to FF for each of them (decimal equivalent: from 0 to 255). 0 being the lowest amount of a given color (let's say 0%), FF the highest (let's say 100%).

Therefore, #000000 is black (0% Red, 0% Green, 0% Blue) and #FFFFFF is white (100% Red, 100% Green, 100% Blue) (Remember in elementary school when you learned that if you mix the 3 primary colours you get white? It's magic)

Composition of a hexadecimal color code

Hex prefix	Red	Green	Blue
#	00 to FF	00 to FF	00 to FF

Deal with transparency

On the web

• If you want to make a transparent background in HTML, you might want consider using RGBA color instead of Hex color.
• If the aim is to make an transparent element in HTML, you should use CSS opacity property.

Elsewhere

Another example, not dev related, if you want to have a transparent brush in Photoshop you would need to adjust your brush opacity, but this will still be independent of the actual color. Then the resulting image (if the chosen format handles the Alpha channel, like PNG), would include transparency.