G1 bias aside, objectively speaking they do look dull compared to the original colours because they don't provide as much contrast. Original Snaptrap's turqoise head is offset by his black head, and the yellow eyes also better contrast against black. The turqoise head here just blends in with the same-colour chest and the yellow eyes don't contrast as well (since yellow is closer to blue/green). This new Overbite has way too much magenta which looks quite bland compared to the original which was predominantly purple which was accented by the magenta upper arms and fists.
A nicer change might be if they painted Snaptrap's faceplate silver to match his
original G1 boxart. I'd consider that an improvement. But the current changes we've seen make them look worse.