Addressing Poor Grooming With An Employee

Good afternoon,
Does anyone have any advice about how to address an employee that has poor grooming? We have a grooming policy in place and the issue is not about poor hygiene but more that some of our female employees just look sloppy and don't make an effort to maintain a neat and professional appearance throughout the day. What is a nice way to say that someone's hair doesn't look nice???? I don't want to offend anyone but I need to find a way to address people while still being "HR savvy!"
Any help is greatly appreciated.

Hi,
Quite a surprise to know that ladies are not maintaining a high std of grooming.
Usually its the males who need counselling on this issue.
Is your org an all ladies org?
Anyways, to encourage people to be smart, you can have random prizes
based on a surprise check in the evenings. The prizes can be ladies stuff like lipstick etc.
Keep a few mirrors at exit and entrance. Can have a monthly well groomed employee prize.

Hi there,
I suggest you initiate some grooming & antiquate training program for all employees so the targeted groups wont be offended.
Or suggest uniform
Suggest a hair style for ladies to wear for official purpose

Thank you to all for your suggestions. This is certainly not an easy situation to deal with but it must be addressed. I am preparing to have a "ladies night" with all of our female staff but will make it kind of like a cocktail hour. I will tell the ladies to come somewhat dressed up and I have asked our hairstylists to come and show the ladies how to do some simple yet professional up-dos. At the beginning I will give a little speech about the importance of grooming and then each lady will have their little session with one of our hairstylists from the spa. Hopefully this will be a fun and informative way to address the issue. Thanks again for your help!