She has neon-pink pillows.
The pillows are neon pink.
Compound modifiers are tricky–to hyphenate, not to hyphenate? I had this issue with the first novel I ever edited, because it seemed there were compound modifiers everywhere. After two chapters of confusion, I finally confessed to myself that I wasn’t certain what the rule was, so I went to Grammar Girl’s website.
She explained that a compound modifier appearing before the thing it’s modifying (neon-pink pillows) should* be hyphenated. If it comes after (are neon pink), it should not be hyphenated.
I re-edited chapters one and two and soldiered on.
*Grammar Girl refuses to use “must hyphenate” or “should hyphenate” in this case. Here’s why:
“Now, the detail-oriented people among you will notice that I didn’t say anyone was right or wrong, and I didn’t use strong words such as should hyphenate or must hyphenate. I chose my words carefully because the rules about hyphens can hardly be called rules; there are so many exceptions it’s making me crazy.”