noun which may take the genitive case particle 'no', noun
free of artificial colors; coloring-free
Used for food, cosmetics, and other products that contain no synthetic dyes or color additives. Often seen on packaging and ingredient lists.
このジュースは無着色です。
This juice is free of artificial colors.
無着色の化粧品を探しています。
I'm looking for coloring-free cosmetics.
着色料 is the coloring agent itself; 無着色 describes a product that does not contain such agents.
Compound of 無 (mu, 'without') and 着色 (chakushoku, 'coloring'). The reading むちゃくしょく follows standard on'yomi.