Alt tags on additional images

All of my products have about 10 extra images under the main product image and I have put the alt text in each one but it isnt showing up.

Can anyone confirm that this works this way or possible to get it to. I want the colour of the item to be shown in the alt text but it seems it just uses the main image alt text on all the additional images. Dont see it on the demo site either.



Thanks

John