Better transparency for cell colours depending on light and dark theme #1878
Description
Describe the problem to be solved
Grist has a light mode and a dark mode. It also has the ability to customise cell colours.
The issue is that there is almost no colour that is adequate both for dark theme and light theme. Dark colours will make the text very hard to read in light mode, and bright colours are a lot too strong for the theme mode. This is especially a problem when you want "hint" colours, meaning colours you can see but that do not change the readability.
That means you have to make sure your team uses the theme team as you if you want more than 2 shades of gray or so.
Describe the solution you would like
The user should be able to specify the alpha channel of the colours. Even if the feature is not perfectly discoverable, this would give the ability to set colours with a small alpha channel, and in this way the colour would be fit for light and dark theme.
Another way to partially solve this issue is to increase the transparency of all colours, or to define different shades depending on the theme.
Illustration
Here is a subtle colour in dark mode:
It is impossible to read in light mode:
And here is a subtle colour in light mode:
Almost impossible to read in dark mode:
