Update Discord Dark theme, improve colors

[Oha-you]

There are some problems with current Discord Dark theme:

• Default text color is #ffffff, even though Discord uses an easier to the eyes shade #dcddde
• roomlist-separator-color is hidden (has same color as timeline-background-color), which makes inline emoji picker hard to distinguish from the background
• Some colors are not in sync with current Discord client (e.g. sidebar should be a bit darker)

Since both Discord and Element are based on Electron, it's easy to extract native colors from Inspector (Ctrl+Shift+I). That's why I added some values with opacity (8 hex characters), taken directly from native CSS. accent-color is a bit different: I took Discord's official value (#5865f2) and made it lighter with a SASS function:

• lighten(#5865f2, 6) --- can be tested here, for example: https://sassme.jim-nielsen.com/

This helps to achieve a more similar look, but also doesn't make it harder to read highlighted text.

I changed theme title too because otherwise people won't be able to see new colors (see https://github.com/vector-im/element-web/issues/13222). Unfortunately there's no way to remove themes added from URLs as well: https://github.com/vector-im/element-web/issues/13221

Comparison:

Native Discord window


New colors (this PR)


Old colors


Before


After (this PR)


I hope the original author (@dylhack) doesn't mind it 🙂

[Oha-you]

Gotcha, I hope it's okay to mention GitHub username instead of Matrix.

[aaronraimist]

Thanks!