Some years ago I bought some concerete paving slabs 12" (29cm) square. At
the time I had a choice of colour: red, dark grey or light sand colour.
After a while the nice light sand colour i chose just turned to a dark dirty
grey. As I guess the coating to the cement just wore off or 'reacted' with
the elements.

I now need a few more of these slabs and have just seen that B&Q are selling
a similar sized slab for £3.99 that is made from Real Sandstone. Is
Sandstone just as likely to turn the same dirty colour as the cement after a
while or will it be more likely to retain the more cheerful yellow colour?
Thanks for advice.