I remember seeing those in State Line Tack several years ago but haven't seen any lately.  I use the new Tipperary helmet, and a 10 year old girl whose horse is here also has one.  Mine is green and hers is blue!  They are certified helmets and a little sleeker than some.  The Troxel Dakota All Trails is also nice with a western flair, leather band and small conchos.  It seems that the problem is that the kids see the adults not wearing helmets and so....  I wear one because I value what litle brain I have left!  Hope this helps.

Even if all the kids have are the white helmets, they can make them "cool" by adding helmet covers on them.  Here's examples of them:

http://www.thornhillusa.com/helmetCovers.html

They come in anythink from tiger stripes to flames, zebra prints, tye dies, etc.  They can also be found to match the girls' slinkies for western riding.

If you have a handy mom or kid with sewing expertise, they are also fairly easy to make!  Might be a good 4H project altogether!