Discolorations is probably dirty / stained grout.2. 

Try and fix with some wood filler & appropriate stain / poly and a small paintbrush.

However, since  its a rental I might consider Laminate ( stains, turnover, etc. )The Laminate will look nice, then you or renters can add additional carpets in the living room, gives the tenant a little more flexibility for home decor. 

My thought is you can't buy a home with a VA loan that needs floors or is missing the sheetrock.The general idea as that the home has to be "livable"....so they might be ok with dirty or stained carpet....but NOT ok with "no" carpet. 

First review: "Bring your own bedding, firepits don’t work, jacuzzi not too warm, carpets are dirty/stained, loose tiles on deck & top of stairs so watch your step, got bug bites while asleep ..other than that it was a big place for families to hang out."

@Jason Staine,  they say you should learn by others mistakes, not your own....ADxxxta IRA is plan custodian for my solo 401K; would not recommend.I use a different custodian for my self directed IRA and my husband uses yet someone else.  

Maybe bright yellow is popular, but I'd consider something more neutral like a gray.Also look at seal coating the driveway and maybe stain the landscaping timbers.PS - my wife says that my taste is all in my mouth, so take my thoughts with a large grain of salt!

@Jody Schnurrenberger,We started about 2 years ago, and the color has stayed beautiful, no stains or signs of wear and tear. 

And when I changed the bedroom carpets over time it was on their dime from their sec deps because the carpets I bought in the house were finally fully stained by the renters.

Hello all,My duplex has h/w floor under cheap and stained carpet.