It is from the use of oil based paint. Turns out most of the yellowing is supposed to occur in the first year, according to the BM dealer I use.

I used a white that was a bit whiter than I wanted, but still worked. It has yellowed a bit and is a little creamier, it's perfect for me.

I am no expert on this at all, but I was told by my GC and a KD that white LAMINATE cabinets yellowed...don't know about painted wood cabinets though.

I second beekeepers wife. White oil-base paint will yellow. My kitchen uppers are not even white, they are a BM pale blue grey and even these have yellowed: there is a stripe on the face frame of the cabinet. Luckily, they yellow less in sunlight than in darkness. It is the unexposed portions that yellow faster.

What causes the yellowing? I am planning on having my cabs painted a cream/off-white color. Is it only true white that will yellow or should I expect my creamier color to also darken? Now I'm worried that the cabs will end up even darker...

I second beekeepers wife. White oil-base paint will yellow. My kitchen uppers are not even white, they are a BM pale blue grey and even these have yellowed: there is a stripe on the face frame of the cabinet. Luckily, they yellow less in sunlight than in darkness. It is the unexposed portions that yellow faster.