Keeping track of what's going on or what you did in each tab of your iterm2 can be difficult. iterm_tab_colors helps with that problem while making your iterm more aesthetic. It automatically differentiates your iterm tabs with colors.
In this image, the blue tab is brighter because it's the active tab.
First, make sure you have iterm2 shell integration with utilities installed. See this page for instructions. If you can execute it2setcolor, then you are good to go.
Secondly, install the fish plugin itself.
with fisher
fisher install patrickf1/iterm_tab_colors.fish
or with Oh My Fish
omf install https://github.com/patrickf1/iterm_tab_colors.fish