but asleep
if you are shooting in manual, you can take a pic of something white (i use a coffee filter) then turn your white balance setting to manual (mine has 2 triangles, but i have a canon). then go to your menu and there should be an option for picking the picture (the white one) to use as the white balance. it will adjust the wb and won't look yellow. it sounds complicated but it's not once you figure it out.
you can also change it in an editing prgram, but it may not look as good.
clear as mud??