Variegated hair... Having hair that 'fade' into streaks of different colors, like salt-and-pepper hair.
Feels like I've soiled her somehow... Typo: the kanji 汚 is written as simplified Chinese 污. 汚れた("stained in (me)") also sounds a bit off. 汚された would be more natural.
What's the matter? Having that look on your face? I'm happy to be stained in your colors, Hatsu-san. Typo: the kanji 顔 is written as traditional Chinese 顏. Grammar is also a bit off at the end.