Frame it in, dry it in and do a decorative item that will make it look like it is supposed to be there.

Which speaking of layers, you have to wait for the individual layers to dry.2.

Even changing just the one board to match will be near impossible due to color variations even with boards from the same box and more so, over time the colors have changed due to wear and drying out. 

., folks seldom pull back the carpet to dry the floor below if there is a leak/spill/pet - hopefully, they address what is visible and accessible; down the road, when carpeting is removed, the boards below are beyond salvaging).

Climate change is only going to make these areas more and more dry in the next five to ten years.https://egis.fire.ca.gov/FHSZ/ 

After 5 contract extensions for reasons way beyond my control, the ink is finally drying on an FHA financed quad, bringing me to 6 units.In March of 2016, 2 months after my 23rd birthday, I bought my first property (a duplex) using FHA financing.  

There is a link to the pdf version of the product manual (see source link below), but here is the info. from page 5 regarding the sub floor:  "Subfloor preparation: The subfloor surface must be smooth, flat, dry, clean and solid.

For materials where the quantity needs measured and there will be waste, provide the make, model, color, finish, etc. but make the Contractor measure and be responsible for the QUANTITY.Examples of these types of materials are:Counter tops, Roofing, flooring, any sheet goods (dry wall, paneling), paint, siding, and framing materials, deck lumber.   

Back in 2014-2015 they were all foreclosures, bank owned, short sales etc.. that has all but dried up out there. 

@Lex Phumirat the answer to your question is not cut and dry.