Looking at a red crowd level 7 with AM EMH or a green level 8 day. Its spring break so I am thinking the red 7 with the extra hour will be more beneficial for us.
There are a lot of variables to consider, but I think one of the best pieces of advice for this situation would be: there's not much difference between a 7 and an 8 - what matters is that you have a good plan in place.
Be there at rope drop, hit the headliners early, and stay ahead of the crowd. If you can, head back to the hotel in the afternoon and (if you chose the park with the morning EMH) hop to another park in the evening.
But if you're not a "commando," you may prefer sleeping in and arriving later. Just know you'll have to adjust your expectations. The short answer to your question is really just a long list of other questions.
For us - we go by numbers. 7 is always less than 8. But we hate crowds, so we search for 3's and fewer. I don't pay any attention to the red and green.