Ahh, gotcha.
If you want the buttons from the dark version but with a lighter colour scheme, do this:
1. Click Preferences (at bottom right of screen)
2. Click Flavours (at left of screen)
3. Click GLITCH EDITION (at left of screen)
4. Near bottom of screen from the menu labelled "skin" choose the option "Mastodon Light"
5. Click the "Use this" button below that
This will give you the extra buttons from the "glitch" version of Mastodon, but with the light colour scheme.