Depends on the colour you're painting the house! Personal view is that cream might look odd against white, and if you're painting the house pink [as a matter of interest, why do people do this? Ireland has the wrong weather for pink houses!] then I don't even want to think about it... but it's a thoroughly subjective judgement. I have seen cream-painted window frames looking very well, so I don't think they're an abomination or anything!
If it's an existing house rather than new build it might be worth patch testing the colour scheme at the back, just to give yourself an idea.