I used OSMO neutral polyox on my shed and has darkened it quite a bit. But the sun realjy bleached the cedar planks. The oil for the floor darken slightkybut this was oak. Yuu can get small tester pots. OSMO has many products for all applications, pick then one that suits interior flooring. Be careful with the tint, as said neutral darkens the wood with each coat. The first coat will soak in quickly.