The greatest artist I've known once said that blank canvases are more afraid of passionate painters who once and for all knew how to broke the spell of "you can't do that"— and i do agree.
These canvases, these blank, white spaces will stare at you until you end up nothing but paralyzed and intimidated.
You may be afraid, but you are an artist.
Show those canvases what you can really do; splash any color if you have to because the truth is, those canvases are more afraid of you.
They are more afraid of the artist who, once and for all dared to break that spell.