changing color of notches base on progress value

[sahar-hoseinkhani]

I have a half circle view and wanna change color of notches base on the value of progress.
for example I want the notches to be in light gray color by default and then change color of 25 percent of notches from start angle to green but the rest 75 percent notches stay in light gray color.
how to achieve this?

any helps would be appreciated