This is so simple I'm sure it's been suggested many times before, but I'm just popping in quickly between other things after (or sometimes during) a session, so apologies for not taking the time to search out other threads where this has been said:

I think we should be able to see planet data (size, unique attributes if any) when getting a colonization event. Making an informed choice requires having all available information!

Before I go though I also want to say that I think players should have an option to put off this choice until the end of the turn. This last point may seem minor, but there are times late in the game when I hit next turn thinking about military strategy and trying to remember where I want to focus ship building, to have to stop what I'm doing and consider the nearby colonies, think about what I want to the colonies to focus on or specialize in because I can't leave the event without making a choice sometimes makes me lose my previous train of thought.