if you say where you are - people may have a beter guess at the wood used to build - historically in you region - in the northeast it was often hemlock

Using one continuous floor material is a good choice. It will open up the rooms and look more up to date. Have you looked at bamboo? It wears like iron and is avaliable in a million finishes. For color, I'd suggest you keep to a shade that compliments the furniture (Cherry/Mahogany) but lighter. Another idea would be to introduce something different. Shades of Gray for wood, Honey bamboo, or even cork might be a good choice.

Can we see a larger section. Is the wood naturally this color or was it pickled. Are there any knots in the wood? It reminds me of pine, but with no knots. That would also explain it being soft.

all different, but all the same wood. Acacia. these are natural. some flooring comes in different stains/tones. buy from a reputable flooring place (not lumber liquidators!) just google Natural Acacia Flooring for the different looks The top one you like is here" http://www.flooringportland.com/acacia-collection-natural-engineered-handscraped-dansk-hardwood-flooring/ i have that exact flooring but in the reddish tone (I wish I had seen this natural, I like it better) I got my flooring about 8-10 years ago. As you can see, the dog's nails did a number on it! She would run and try and make the turn at full sprint!