colour, colourful, coloration

In such words as colour, Canadians generally prefer the British ending ‑our to the American ending ‑or (as in color).

• Dominique doesn’t want to colour your opinion by telling you what she thinks.

Words formed from the root colour are also usually written with the ‑our spelling in Canada.

• The newscaster used a colourful turn of phrase to describe the thief’s actions.
• Cobalt was added as a colourant to the figurines and ornaments.
• Each spring, the tap water at the cottage is discoloured.

However, the u is usually dropped in the words coloration and discoloration.

• The discoloration of the wallpaper was due to a leaky pipe.