varnishing varnished/stained floor help

[ilovechristmas1]

hi,im doing a bit of decorating and in my lounge the floor has been varnished or stained (not sure which) would say its not shiny,sought of orange.reddy colour

anyway could i varnish or stain to a darker colour without sanding

painting it has crossed my mind but im even more clueless on that subject

many thanks