Adjust "Dimidium" color scheme

[dofuuz]

• Add Selection BG color
• Make Bright white brighter

Summary of the Pull Request

Final tune for Dimidium color scheme before its release.

References and Relevant Issues

#18563

Detailed Description of the Pull Request / Additional comments

I made little change to Dimidium color scheme.

• Adjusted "Bright white" slightly brighter, hoping it can be distinguished better from "White".
• Defined "Selection Background" color.

This will be the final tune for Dimidum color scheme.

[DHowett]

Woo, thanks so much! I'll mark this one up for inclusion in 1.24 so that when it goes stable it's updated there too.

Wondering if I should backport the entire theme into the 1.23 Stable release...

[ehoogeveen-medweb]

I was checking out the new theme, and the other thing that stood out to me as lacking contrast is the -w in diff -w:

Compare Ottosson:

While I wouldn't want the -w to be too dim as that would make it hard to read, it's hard to see that it's a different shade of gray at all with the current scheme :)

[dofuuz]

@ehoogeveen-medweb Are you using 'Automatically adjust lightness of indistinguishable text' option?

[ehoogeveen-medweb]

Ah, I was! I didn't realize that would have an effect on it. Yes, setting that back to "Automatic" makes the -w much more distinct: