If you desire a blended look for the room with colors that match in the upholstery walls and accessories choose an area rug that matches the color of the floor.
Rug color for dark brown floor.
Couch color is a light linen color and chairs are a charcoal grey the in my opinion looks cooler blueish.
The best rug color for a very dark floor.
If you are choosing a rug with a pattern it should contrast with your flooring.
Dark wood flooring screams out for a lighter natural shade such as a brown or tan while a lighter wood will benefit from darker richer tones.
And our floors are a dark brown.
This rug on a dark espresso floor would probably not look as good as it does against the light background of the sisal rug which also seems to be the same colour as the wood flooring in this room.
Speaking of light colors the main reason for a light rug on a dark floor is to provide a space in the deep brown.
Keep the colour of your wood flooring in mind.
Go minimalist and modern with wide plank stone.
But if you find a rug like this with a light border who cares what else goes on in the middle.
A dark floor grounds a room and deflects attention to lighter or brighter colors and interesting textures.