I'm starting to wonder if, that for ROTF, Hasbro are deliberately moving the toys away from their on-screen colour designs. For the first movie, even with the limited time Hasbro had to convert the movie designs into toys, the toys matched the designs as much as possible within the boundaries of cost and time available. The basic colours were all very real world to the movie images even if the designs and paint applications weren't quite as detailed or accurate. All of the decepticons were rather drab colours. Although the autobots were more colourful, the colour came from their vehicle modes while the robot parts tended to be shades of grey & black. For ROTF, the toys seem a lot more colourful, with less real-world colour schemes and are far from accurate to the cgi models. For example, Sideways has a lot of bright red in robot mode that fits more with the colour schemes of other TransFormers series rather than the Movieverse, not to mention that the red isn't present on Sideways in the movie clips we've seen of him. Similarly, filming pictures showed the Arcee bikes to be mainly black with some detailing in blue, pink or purple. In toy form, Chromia's bike is mainly blue and Arcee is mainly red (not pink or purple.) This makes the toys different and more colourful than the actual film. The Skids toy has two very different shades of green while the cgi model seems to just have the lime green. The Mixmaster toy has bright purple windows which I doubt he has in the movie. Hasbro have said previously that bright colours attracts the kids so maybe they've sacrificed movie accurate (drab) colour schemes to make more eye catching toys. Just a thought...
Yes..I believe it's to create more eyecatching toys. If you look at the Constructicons, for example, you can see Mixmaster has purple windows, Rampage has red. Sideswipe has dark blue windows, but Sideways has dark red. They could have gone with standard blue windows but this way the bots are more versatile in colors and look less dull next to each other. Personally I think if executed right it can be the perfect mix between on-screen accuracy and toy appeal. Sideways: win. Dead End: fail.
I concur. They are trying to make the toys "jump" out at you when sitting on the shelf and this is def one way to help do that.