I have Alexandria Beige in my master bath. There is a small window in the shower area and no natural light in the vanity area. This color is very pretty and elegant, with an undertone of olive, although the chip does not read that way. But it is more the tone of coffee with a bit of cream as to darkness. Kind of a medium tone rather than light if you know what I mean.

The bedding appears to me to be a brown figure on a light blue background; is that correct? If so, I would prefer a light brown for the walls (use the grey in the guest room!).

Do you have the bedding yet? I recommend waiting until you have it to choose the wall color. They don't have to match but they need to be compatible. For example, brown is brown but a greenish brown (khaki) and a reddish brown may not look right together. Since the hues of paint are more variable than those of anything else, it is usually best to choose fabrics first, then paint. If you can place samples of the paint colors next to the bedding you'll probably be able to choose almost instantly.