集合视图行颜色在滚动上更改

I have this collection view and i've set the color of it's rows when drawing each row based on it's index. It shows correct color for each row until you scroll down and then go up again. For example if it was in order of R,G,B,R,G,B when scrolling a little bit up and down it might be G,G,R,B,R,B. I have tried setting rasterize layer to both true and false but no luck there too. I don't get why this happens and how to fix it. Because i set the color on cellForItemAt function and it should get called whenever drawing a row again and basing the row color on a list of colors and id of that row it should draw same thing always.I have this collection view and i've set the co