Different color on auto page number

Hi, I'm currently designing a book for a local campus, and I'm having trouble making a different colour with the auto page number.

For example, I have 35 pages on the first chapter, and on pages 3-4 and 23-24, it has darker colours than the other, so I have to make the page number lighter. 

Is it possible to change the page number colour using the auto page number? Or are there some techniques I can use? 

Many thanks for considering my request.