Added blue, red, white, etc. functions

Added functions with the name of each color.

I believe this makes it easier to mix many color in a line when printing:
```lisp
(princ
 (concatenate
  'string
  (yellow "Five") " test results went " (red "terribly wrong") "!"))
```
Instead of:
```lisp
(progn
  (with-color (:yellow)
    (princ "Five"))
  (princ " test results went ")
  (with-color (:red)
    (princ "terribly wrong"))
  (princ "!"))
```

If you're willing to accept this merge, I can write a few tests and some documentation too before you merge it.