This is a natural wood product and will fade to silver grey if left untreated. It is prefectly acceptable to leave it like this. You can stain your furniture any colour using a water based wood furniture stain. (Follow manufacturers instructions). Teak oil is also suitable. It is not uncommon, for small splits or shakes to occur in the timber or slight warping in quick drying weather conditions. These will normally go back when humidity rises. This is nature at work and is perfectly normal. It does not affect the strength and durabilility of your furniture.