Had a professional flooring contractor come in to refinish original 1903 heart-pine ”subfloor”. Same contractor refinished the oak in my first floor and did a very solid job, on time and mostly on budget. I’m very happy/impressed with a number of major repairs upstairs, but one area in particular looks wildly uneven depending on how lighting hits it.

The color varies widely even within the same board. He indicated this was a consequence of sun bleaching making the stain appear uneven (“It's not a stain issue. It's sun staining where something used to sit on the floor. Most pine floors I do end up with the same thing.”) .

I thought sufficient sanding would make everything even initially then sun bleaching could occur after over time.

I’m generally inclined to trust the contractor based on excellent interactions, just want to be sure I’m not missing anything obvious/this isn’t a blatant avoidable mistake.

On a related note ... he’s still due back to install and finish ~80sqft of new wood. He asked for payment in full ($2100; the entire contract is $2800 and I’ve already paid $700). I told him I assumed some portion would remain outstanding until the job was completed. He suggested I pay $1600 of the $2100, leaving $500 upon completion. Is this reasonable?