Yes, bluer is a Scrabble word!

Adjective

1. Of the color intermediate between green and violet; having a color similar to that of a clear unclouded sky

2. Used to signify the Union forces in the American Civil War (who wore blue uniforms)

3. Filled with melancholy and despondency

4. Characterized by profanity or cursing

5. Suggestive of sexual impropriety

6. Belonging to or characteristic of the nobility or aristocracy

7. Morally rigorous and strict

8. Causing dejection