From colour + -less.

• (British) IPA: /ˈkʌlə(ɹ).ləs/

colourless

1. Having little or no colour.
   • 1867, Ivan Sergheïevitch Turgenef [i.e., Ivan Turgenev], chapter I, in Eugene Schuyler, transl., Fathers and Sons […], New York, N.Y.: Leypoldt and Holt, →OCLC ↗, page 1 ↗:

     The servant to whom he put this question was a young fellow with chubby cheeks, small, dull eyes, and a round chin, covered with a colorless down.

2. (of a liquid) Water white.
3. Lacking in interest or variety.
4. (politics) Neutral in opinion or allegiance; centrist

• (having little or no colour) see also Thesaurus:achromatic
• (of a liquid) clear, waterlike; see also Thesaurus:transparent
• (lacking in interest) drab, dull; see also Thesaurus:boring

• French: sans couleur, incolore
• German: farblos
• Italian: incolore
• Portuguese: incolor
• Russian: бесцве́тный
• Spanish: incoloro