Muted is a perfect description. The lack of sun, almost constant cloud cover and moisture/slight fog in the air always makes all of the vibrant colors seem dull. Muted. It's like having your RGB color ranges only go to 128 instead of 256. Then summer comes and everything is bright and colorful for 3 months, and everyone has a smile on their face again. They might actually say, "hello."

For me, April to late September is perfect in Seattle. My only gripe is the month of continuous rain in the winter.