Abu Dawud and an-Nasa'i have an addition:

"nor be dyed (with Henna and the like)."

وَلِأَبِي دَاوُدَ, وَالنَّسَائِيِّ مِنْ اَلزِّيَادَةِ: { وَلَا تَخْتَضِبْ } [1]‏