white as a lily

soft lily-white skin.

pure; untouched by corruption or imperfection; above reproach

He tries to pass himself off as some sort of lily-white saint, but he's not.

designating or pertaining to any faction, organization, or group opposing the inclusion of blacks, esp. in political or social life.

a member of a lily-white organization, esp. a member of a former faction of the Republican party in the South opposed to the inclusion of blacks in the party or in political life in general.

adjective

blameless , good , irreprehensible , irreproachable , unblamable , angelic , angelical , clean , pure , sinless , unblemished , uncorrupted , undefiled , unstained , unsullied , untainted , virginal , faultless , guiltless , harmless