Board Game Arena

I have searched all the rules for an explanation of why a specific colored marker is disabled in the game for me to select and can't find an explanation. It usually happens late in the game when I have to have that color to circle a ladybug, and that's the color that gets disabled for me.

If I'm first, I can't pick it but it shows up on top like it's available. I believe my opponent can select it.

If I'm not first, if my other opponents have selected something other than that color, I am simply not allowed to pick it.

I keep on losing becuase I don't know the rule so I don't know how to strategize around it!

It probably means you can't use it. Do you have a screenshot of the situation?