Transformers have changed color schemes before but not usually with every single new incarnation of their character. Optimus has occasionally not been in his normal red and blue. War Within Sentinel Prime was yellow. Animated Sentinel Prime was blue. Movie Sentinel Prime was red. Transformers have also changed their appearance entirely but mostly they are all homages to some other version of their name sake. Megatron is really the only character to excessively not homage himself except in Animated when he was a homage of the Movie who turned into a homage of G1. Out of the 3 Sentinel Primes you'd be hard pressed to tell they're suppose to be new incarnations of the same character sense none of them look anything alike. And oddly enough this is probably the one character that I can say without hesitation I like the movie version more than the others... at least in design not in personality. Finally, Transformers have also been know to change personalities with new incarnations of their character though they tend to keep some personality traits that are the same. From what I hear of War Within Sentinel Prime all he does is die at the beginning of the comic to make way for Optimus to take his place. Animated Sentinel Prime is a jerk who thinks he's better than Optimus and has an irrational fear of organics. Movie Sentinel Prime is a jerk who likes Optimus but betrayed his own people and tried to enslave the human race. Well if they have anything in common it's probably that they're all jerks though I can't confirm that War Within is also a jerk like the other two. So I think Sentinel Prime is the most inconsistently portrayed character in Transformers... Unless you can think of any characters that are even more inconsistently portrayed. Megatron I'd say has a spot at number 2 because his designs are all over the place but he's consistently portrayed as the Decepticon leader so that kinda disqualifies him from number 1.