Hi Jennifer, I've moved this post to AD, since it's not a class question per se.
The easiest way would be to add a cream Solid Color layer set to "Color" blend mode.
Let me know if that isn't satisfactory, and we can explore a more complex method.
You can't leave the resolution field blank, nor do you need to. It doesn't matter what you put in there, it's completely meaningless, I promise. 300, 200, 100, whatever.
Ok, let's get the big things out of the way first. Have you checked that the calibrator isn't faulty? By calibrating another computer in the house with it?