Here is finally conclusive evidence that there are indeed considerable differences between the two haircuts. Tom's hair is a shade darker and Carol's has slightly more body - possibly due to the two using different shampoo and conditioning products - Carol uses Johnson & Johnson brand while Thomas uses the natural oils from his body which Lillian harvests for him using a custom made spatula.
This enlargement shows Carol Brady's hair has a slightly redder tint than Tom's with highlights towards the sides.
This photgraph shows Tom's hair does not have highlights towards the sides and could be described as having a consistent colour.