Why are my Terminal.app colors different from iTerm?
There has been some discussion on the web about iTerm2's color accuracy being off,


https://github.com/altercation/solarized/issues/257
https://stackoverflow.com/questions/7278267/incorrect-colors-with-vim-in-iterm2-using-solarized


Including a bug report on iTerm2 issue tracker, https://gitlab.com/gnachman/iterm2/issues/3989.

Sounds like it might just be a iTerm2 issue.