942630 - Default theme should not use HSLA colors, use RGBA instead

Status: RESOLVED WONTFIX

(Firefox :: Theme, defect)

Description

[patrickjdempsey]

Inspecting work being done in Australis, I've noticed a proliferation of HSLA colors.  As HSL is not human-readable, it makes it very difficult to scan through lines of default theme code to quickly figure out the origin of a blue line for instance.

This not only impacts Themes, userStyles and extensions, but it will be a maintenance headache for Mozilla in the future to extract the exact colors in order to change them.  

RGB is human-readable for anyone with a vague understanding of how it works.  HSL requires a color-chart in the exact same HSL standard (of which there are several).  RGB is the native color space of monitors.  Also, HSL is translated from RGB, so it's an unnecessary step in both directions to convert HSL to RGB and back again.

Comment 1

[:Gijs (out until Jan 5th; he/him)]

Stephen, do we want to change this? I don't know enough about this to make a call here.

Comment 2

[Stephen Horlander [:shorlander]]

I disagree that HSL is not human readable. At least, not any less readable than RGB. AFAIK HSL works the same across browsers; so if you understand where 0 sits and where 360 sits on the spectrum, how saturation works and how luminosity works it is much easier to play with the values to get tones and shades. That is, the values have a clear and meaningful relationship. The first value sets the color, the other two affect it. Which is not the case with RGB or HEX.

I don't think it really matters what the final color value format is. However I don't think we should base that on what is human readable since none of them are particularly friendly in that area without some knowledge and experience of how they work.