Here's what we were starting with:
We decided to paint the two rooms the same color in order to tie the spaces together. My mom and I had been consulting by email, phone, and mailed paint chips, and thought that a light gray would brighten the spaces up and minimize the yellow cast. I was overwhelmed by the number of gray paint swatches I liked, so made a semi-arbitrary decision to limit the field to Benjamin Moore's Historic Colors line. I had been browsing the internet for pictures of paint colors I liked, and had asked my mother what paints she had used in the past, and was repeatedly frustrated when a color I liked was no longer in the company's catalog. The historic colors don't change, so I'll be able to easily pick up a new gallon of paint anytime I need to touch something up.
From the Historic Colors line, we selected the Wickham Gray and Stonington Gray to test. I followed my usually procedure and painted swatches on various walls with different lighting conditions. These two grays, more than any other color we've tested, are amazingly changeable depending on light and setting. The Wickham ranges from a light blue to a light taupe, while the Stonington swings from a light gray to a mid-range charcoal to a medium lavender. Fun! We liked them both, but settled on the Wickham (the lighter one, on the left). (I just want it on the record, after the bedroom paint debacle that you haven't even heard the half of yet, that we are usually capable of choosing a paint color!)