。
I don't like that school's school colors.
Literal
I [topic-は] that school [of-の] school-colors [subject-が] not like.
スクールカラー is a wasei-eigo (Japanese-made English) compound — 'school colors,' meaning the official colors representing a school, used on uniforms, banners, sports teams. Borrowed concept from American/British school culture but used in Japanese. 好きではない is the polite/neutral negative of 好き.