THEY ARE THE COLORS OF both the light in a Dutch still life and the urn it illuminates. A daddelion in full bloom and one gone softly to seed. Sunny and steely, dialed up and dulled down, the combination of yellow and gray makes for a contrapuntal dance that's neither too aweet nor too subdued. Add hints of clean white to the mix for surh things as china, tablecloths and stationery and you've got it made in the shade--and in the sunlight.