yellow is golden...

...sun. But yellow has obvious drawbacks. Most shades of yellow text should only be used on dark backgrounds. Of course, yellow can be a fine background color. Enough said.

Yellow is warm and happy and stimulating. It can certainly add a bit of zest to a dull color.

Yellow. Use it to add warmth and to add excitement when a color combination is too cool or too boring.

Combined with bright colors, it can be really snappy. And it can add some traditional warmth to otherwise cold, sterile pages.

Yellow is the sun... gold... lemons... daffodils... golden wheat fields... leaves in autumn... phone book pages... Yellow can be very pale, bright, deep and golden or mellow, but it almost always warm.