For the skin tone, I use different color palette: dark brown, light brown, beige, light pink, peach, orange, yellow (I also use black but not here)
I always use colored pencils because I don't have copics!
I start with the shadows (dark brown and light brown) then I color all over the shades with beige, peach and orange (not too much for Sasuke, he has more pale skin than Naruto). Don't be too hard on your pencil!
And finally, I add a touch of light pink for Sasuke (the lips too) and a light yellow for Naruto but just a bit. ^^