Understand this though epcotty, when we went back in 2011, I used easywdw to check crowd control. Our first day in the parks was a Sunday and we chose AK because it was that park's EE day. easywdw had AK on red that day which means NOT to visit. We met a TON of characters that day...all before 10 a.m. with minimal or no lines. We went home around 1pm returned around 6 or so and still had little to no lines on a red day. I suppose sometimes you just get lucky.
Same goes for MK. It's red day while we were there was Monday, but we did it anyway. Park didn't start to get crowded till 1pm when we were leaving. We returned on Tuesday AM to finish what we started and again, park didn't start to get crowded till 1 pm. The calendars do help with crowd control, but again you just never know. I think we used 2 fastpasses the whole time we were there at MK. And maybe two fastpasses at AK. As a matter of fact, I have one of the AK fastpasses with my memory stuff because we never had to use it when returning to AK.
This is true. If you are going to do rope drop and late evening and leave during the most crowded part of the day, you may not notice the crowds anyway.
You have to remember the recommendations are subjective. "Red" doesn't equal crowded. "Red" only means that there is a high probablitity that the "red" park will be more crowded than all the other parks. The above poster had a great time at a "red" park, but that doesn't mean the prediction was wrong. That park may have been the most crowded of all the parks, but overall all the parks may have had low crowd levels to begin with. For instance, if all the other parks are crowd level 1 or 2, and your "red" park is level 3 are you really going to feel like it is crowded? Probably not. Does that mean the other parks aren't less crowded? No.
Also, the way the poster toured would have made the parks seem less crowded to begin with. Early morning hour rope drop is a huge advantage. I would expect anyone who tours like that before 10:00 to report getting a lot done, no matter what the color or crowd level. The park was most likely designated "red" becuase it had early morning hours which causes large numbers of resort guests to flock to the same park. You won't see huge crowds in the morning as most people on vacation don't like to get up. However, as the day goes on, you will start to notice a difference because you've already attracted extra resort guests to this park in the morning, and then you start to add in the sleepyheads and the day guests and it gets busy fast. How busy depends on crowd levels for that time of year, but definately bussier than a non EMH park. This is why unless you specifically want to experience the early hours, Josh advises against those parks. His advice if you want to hit those parks is to do exactly what the above did. Hit the early morning hours, then when it starts to get crowded leave for a "green" park or head back to the hotel for a break.
You also need to factor in which park you are talking about and which attractions you plan on doing. For most people, AK is a half day park, so even a crowded day only drags the park out to being a full day for them. Also, meeting characters at AK, touring the animal trails/petting zoo, completing the badges, and seeing the shows aren't really things that are affected all that much by crowds until you get into the peak season, so I wouldn't expect anyone to have a very hard time touring AK even on a "red" day. If you plan on hitting lots of shows, parades, ADRs, and fireworks or taking in Innovations and World Showcase for the day, you probably won't care if the park is marked "red" or not as those types of attractions can handle crowds better.
All this is why I usually end up using a combination of TP and Easy when planning.
I like to look at the historic overall crowd levels for this time of year and also each individual attractions historic wait times. In general, I want to know are we looking at crowd levels over or under 5 and how far over or under? And then what my worst case scenario wait times will be for mid day. Are we talking 30 minutes or 120 minutes? This gives me a general idea of how crowded it will be and how long the waits will be in general for my whole trip.
Then I like to consider the red / green recommendations and the
why for my specific days. This way I can factor in if a day is red because of an event or EMH or what and plan accordingly. The why of the crowds is more useful to me than just a number becuase it helps me plan my days out better. Like the above poster, there may be a reason I want to go with a "red" park over a "green" one. For instance, if I am going to take advantage of EMH or I really want to see or particiapate in a special event that is bringing in crowds. If I know overall levels are 3-4 for my whole trip and the only reason a park is red is EMH, I may go there anyway. However, if the overall levels are 4-7, I will probably avoid that park except in the case of morning EMH, but then I will definately hop to a "green" park around lunch.
In the end, I think you need to look at the whole pictuire when planning, not just a color or a number.