As far as I understand, this is a Colorsublime issue, but I could be wrong
I just upgraded Sublime to the latest build. Now all of the Colorsublime color schemes show the keys and values of YAML files with the same color.
Lazy Scheme (for example)

In previous Sublime versions, they were different.
Here is a screenshot from the native color scheme Breakers (not Colorsublime)

As far as I understand, this is a Colorsublime issue, but I could be wrong
I just upgraded Sublime to the latest build. Now all of the Colorsublime color schemes show the keys and values of YAML files with the same color.
Lazy Scheme (for example)

In previous Sublime versions, they were different.

Here is a screenshot from the native color scheme Breakers (not Colorsublime)