Seeing the following when loading the color scheme:

Error detected while processing function 26_Hi[49]..26_AddAnsiGroups:
line 18:
E254: Cannot allocate color 0
E254: Cannot allocate color 0

I've confirmed that the terminal can support true color.

Using vim 8.1 on Ubuntu in a WSL2 environment. Tested with and without tmux with no effect on the errors.