How to store a function in a constant?
You pretty much need a helper function to do that; a small local function that calls strip.Color() with the intended arguments and returns strip.Color()'s return value if there is any.

int first_color(void)
{
   return(strip.Color(0, 60, 0, 0));
}


(assuming strip.Color() returns an int) which you would call with:

value = first_color();


If strip.Color() is a void function, then delete the 'return(' and one ')', fix the definition of first color to be void instead of int, and of course, don't try to use any return value from first_color().