Google: We spell it colouring here
Do a search for colouring, and of the first 10 results:
- 7 spell it coloring
- 3 spell it colouring.
I suppose you could argue that the relevance of the information is unlikely to be affected by whether the site uses US or UK spelling for a search time like this.
On the other hand, get your spelling Sherman T20 tanks off our lawns (or yards).
As you can see, after the image results the first one spells it coloring. And don't get me started on all those Disney and Simpsons image - ie American - results ...