No but ultimately specifying it in two places could be better.

So first off if you want it to literally be the same then you could do something like:

  h1, button {
    color: #343434;
  }

That would make them the same. You could also do

  .primaryColor {
    color: #343434;
  }

Then set the elements which should have a primary color with that class.

But if you could break my first example apart and set it in two places just as easily. But that's setting it at a high level element itself. You could even go crazier and set EVERYTHING to that color but ultimately many of these decisions have to be context based to decide.