Wordnet 3.0
ADJECTIVE (1)
1. 
 of the color intermediate between green and violet; 
 having a color similar to that of a clear unclouded sky; 
- Example: "October's bright blue weather"- Helen Hunt Jackson- Example: "a blue flame"- Example: "blue haze of tobacco smoke"[syn: blue, bluish, blueish]
WordNet (r) 3.0 (2006):
blueish
    adj 1: of the color intermediate between green and violet;
           having a color similar to that of a clear unclouded sky;
           "October's bright blue weather"- Helen Hunt Jackson; "a
           blue flame"; "blue haze of tobacco smoke" [syn: blue,
           bluish, blueish]