When you view overview and see the entire world, I would like there to be an option to display instead of alliance lines, to display them in colors.

What I mean is; say there are four countries (pink, red, orange, and green) in each corner of the world, they're all in the same alliance with a bold brown line connecting all four.
Instead of the brown line, turn all four countries into the same brown color to indicate same alliance, apply this to all alliances and their respective countries. non-allied countries are labelled gray or a color meant for countries without alliances.

Sometimes the lines clutter up the map and it can be difficult to see which country belong to which alliance.

To do this is a really hard programming problem called the 4 color map problem... ick. I would not want to have to implement it.

It could be coded to use a large number of colors, so the four color theorem wouldn't apply.

However, it would still be extremely intensive (and lengthy) on the server to dynamically create a image up to 33 millions pixels in size every time someone views an overview. Drawing a few lines connecting countries, however, is fairly quick and painless. So, I'll have to stick with that method.

OK.

How about choosing to only see one alliance on the overview? It's nice to see every alliance and their lines but sometimes I would like to see one or two alliances instead of all of them. Maybe a list of every alliance and a checkbox to either view or hide their lines.

I'll make a note to look into that option.