Hi, If it is genuine lineoleum, the colour and pattern should continue down throughout its thickness. However, fading colour/patterns is often due to a bleaching or alkaline agent having been used in cleaning it. I suggest, on a test area, ensuring the surface is free of chemical residues and absolutely dry - apply some metallised emulsion floor dressing (high solids will last longer) which will take around an hour or so to dry. Sometimes this can enhance the lino's appearance. If it works in your case, apply a second coat and allow to dry. Buffing not necessary but a light buffing can be carried out especially between multiple coats. Hope this may keep your customer happy.