Fill in the blank with the correct Canadian spelling: Amy's favourite __ is blue.

The correct answer is "colour" because it reflects the Canadian spelling convention. In Canada, words that are derived from British English tend to use the "ou" spelling, making "colour" the appropriate choice. This aligns with how other words are similarly spelled in Canadian English, such as "favour" and "neighbour."

The other choices represent American English spellings. "Color" dispenses with the "u," which is characteristic of American spelling conventions. Similarly, "favorite" utilizes the American spelling without the "u," whereas the Canadian version is "favourite." Lastly, "flavour" would also be correct in Canadian English, but since the blank specifically pertains to a word linked to the options provided, "colour" is the one that fits best in this context. Thus, "colour" is clearly the word that aligns with Canadian English standards.