That doesn't make sense, as full throttle is definitely faster than the blue area at any other time I tried it. I always go full throttle, and blue when getting close (unless the blue area has a period of being at the top of the maximum speed range?).
Top maximum speed is 2001 clicks. You don't reach this speed an the travel to hutton orbital. You reach only between 1800 and 1900 clicks as far as i remember. It's been a while.....