How to create an optimized regular expression?

In another thread, someone had asked for a script to validate an input against the list of 140 standard named colors. Initially, I just stuck the whole pipe-delimited list into a regular expression /^(...|...|...|...|...|...|...)$/ and declared it done. But that seemed rather bulky, to say the least. As an alternative, I alphabetized the list, then used parenthesized subexpressions for common prefixes to make the whole regular expression more compact /^(dark(...|...|...)|light(...|...|...)|...|...)$/. Later, I recognized that many colors rhyme, so I produced an even tighter regular expression by grouping colors with the same ending /^(...|(...|...|...)blue|(...|...|...)green|...|...)$/. I expect that there are even tighter expressions possible with a combination of rhyming and alliterative techniques.

I welcome your function that accepts an array of words and returns the tightest possible regular expression. Do you have one or know where I can get it?

removed as lack of feedback indicated that supplied script was not what the O/P was looking for and is therefore clearly redundant...