So I wanted to figure out how many possible combinations of colors PAREO's hair could be, so here's the math:

There are 256 values of each of the rgb values (it includes 0, so that's why it's 256), so 256^3=16,777,216 possible colors.

Now to figure out how many combinations there can be. This is where I resort to looking up the equation online. That leaves us with 14,073,747,996,672 (14.073 trillion) possible combinations of hair colors. Lets say she changes hair colors every hour (This part is just to show you how ridiculous that number is). That's still ~1,606,592,237 years. She'd probably go bald before then though.