It's up to you if you want to make a brighter, bolder, jazzier quilt or if you want to keep it on the quiet side. Either way is fine, just depends on the end result you are looking for. Personally, I like the soft colors you are using, they make for a very soothing quilt. If I were going to add anything I would add a very soft pink and green in small amounts so as not to overtake the patterned fabric itself. Reminds me of sitting in the shade of a cool Victorian rose garden on a warm summer day.