You could see Holly's tattoos now and then through the bangles she sometimes wore. The same with Alyssa. In the first three seasons both their tattoos on the back of the shoulders were covered over with make up and the same with Holly's bracelet tattoos.
In From Fear To Eternity Shannen's tattoo was covered with make up too when she steps into the shower.
It was towards the end of season three when they started showing the tattoos on Alyssa's wrist and then in season four they stopped covering them.
But it's odd cause in season five they'd cover Rose's tattoo but you could clearly see it through some clothing in a few episodes. Towards the end of the season they stopped covering her tattoos too
*hugs*
xoxoxo