Yellow. Yellow is the color that you wear when you want people to look but not touch. Come see me, come talk to me, don't put your arm around me. Casting a play? The gleeclub chair, perky and cute and everyone's friend... she needs a yellow dress. Yellow is absolutely the consumate wallflower color - but the wallflower that organized the party and that everyone talks to.
Yellow, like red, is an attention getter. It's a youthful color in all of its incarnations, and it looks best on young complexions. (This is particularly true of caucasians - I haven't been able to wear "my" yellow in a whole garment since my teens. Darker skinned people can enjoy yellow for decades more). Yellow is a competent color. You expect good things from a person wearing yellow. It's a cheerful color - something of the polar opposite of grey.
Yellow is best in fabrics that reflect the tone. A light yellow should be worn in a satin or crisp fabric, a deep yellow in a wool or fuzzy sweater. Yellow is best paired with other, cooler colors. Imagine interviewing a young lady for an accounting position, attired in a grey suit with a lemon-yellow blouse. Clean, awake, classic.
As someone past the first flower of youth, when I want to wear yellow I make sure it's part of a pattern or a trim. Imagine buttercup yellow embroidery on a cornflower blue dress - so simple, so European, so clean and cheerful. Or a snow-white dress flocked with yellow polka dots? A butter yellow loose-knit sweater over chocolate suede? Don't get me started. :D I can pair colors all night long... and then where would we be?