help. newbie needs advice on varnishes/lacqer etc

Hi.
I have attempted to restore a beautiful wood (I think possibly beech but may be oak - sorry but not enough expertise yet) window sill in a conservatory. It had bad black mould and varnish peeling off. I sanded it right down to the bare wood and got a nice smooth finish to it the, after cleaning with spirit I varnished it with Johnstones clear varnish. Only problem is the varnish darkened the wood quite considerably and we are not satisfied with the result as it now looks noticeably different from the skirtings etc. Is it possible to get a varnish or lacqer that will give great protection (tough and durable) but leave the wood as close as possible to the unvarnished colour?? All advice will be very much appreciated - many thanks.

Eddie
ps if yo can contavt me on [email protected] it would speed things up.