Picture Of Brazillan Wax Of Women How Do I Fill Just A Part Of A Picture With The Paintbucket Tool In Photoshop?

How do I fill just a part of a picture with the paintbucket tool in Photoshop? - picture of brazillan wax of women

I try to create diagonal lines and try to fill each with a different color. The problem is that only with lines that are near the coast. How can I adjust so that only fill part of the picture?