I'e recently painted our bathroom floor white and now I need to varnish it to prevent scuff marks, but all the varnishes I've tested so far seem to colour the floor yellow or brown, even when they are advertised as clear. Is there a truly clear varnish?
It sounds like you have been using linseed oil based varnishes, and it's the oil that is causing the colouration. Next time make sure you choose a water-based varnish, often advertised as 'quick-drying'.