The Mexican tile floor on my back porch is turning yellow. Help?

First, has the tile been sealed? There are several urethane coatings on the market that are used to coat Mexican tile. These urethanes are sensitive to ultraviolet (UV) light and will turn yellow. Strip the floor and apply a Mexican tile sealer. Warning: Urethane coatings can be extremely difficult to strip, requiring strong solvents for removal.

TIP Stay away from sealers and waxes that are solvent based. Use only water based products on Mexican tile.