So I’m to the point that a lot of the paintings I started when I first got into the hobby are now finished curing. There one painting in particular where I put in some snow with the knife and this white has a small yellow tint to it now. There was no yellow anywhere in the painting as I just used Prussian blue, vandyke brown, midnight black, and a little bright red. Is this normal? Only painting using that particular tube of titanium white that did that.