In my central Pennsylvania lawn I don't have any Bermuda, but I do have two or three types of grass. They're all different shades of green and grow at different rates. What's the best way to get a consistent look?
"The best" is a bit subjective here, but here is my $0.02.
Some might think that a consistent look requires a single grass species.
However lawns that contain a mix of species and strains tend to perform better than single species lawns. Each species has a sweet spot in terms of sun/shade, aspect, water needs, etc. By having a mix you increase the chances that each location has a grass ideally suited to the "local" conditions.
Different species and/or strains also have different greening-up and dormancy patterns, so while one species may green up early in the spring, it might go dormant sooner in the summer. At that time, a different species might be green - thus extending the "green" for more of the season (especially without irrigation).
While there will be differences in color and growth rate, seed producers are continually working to develop strains that play and look nice together. If you follow a program of annual fall overseeding for a few years (Ideally you'd aerate, apply compost, and spread an appropriate seed mix), you will soon find that the large, highly visible, patchiness will give way to a more consistent look.