IMO the easiest way to brighten a room is with actual lighting so post some pics of the sapce and maybe an explantion as to why dark floors in a dark space .

If this is a single story home you could add Solatube - not a skylight look but brings in a phenomal amount of natural light. Check this link & if it doesn’t work just search Solatube

I have 5 in my home, one has a light in it for after dark. Truly amazing the difference they make in my one story, wide eves, windows all on north or east home.

Do these leak or have condensation issues?

Mine have not & the first 3 were installed 2013 in our new build home we’d been in since 10/2012. In our small neighborhood I know of 5 others who had them installed after we did. They can be installed in 2 story homes easily on 2nd floor & if there’s a closet to go through from 2nd floor they can be installed in 1st floor. It’s the reflective tubing that needs a path to travel through. I have one large one in my kitchen, 2 large in great room, 1 small in windowless laundry & the small one with a light replaced a light fixture in stairwell to bonus room over garage.

Solatubes are a good idea, and no they don't have any moisture issues.

Bring only warm tones into the room from now on, and things that remind you of the sun and the outdoors. Plants and brass, tans and creams, and natural wood tones will complement your blues and grays and dark woods. And warm lighting.

Here are some inspo pics in different styles I like for your space.

Solatubes are fine, but skylights are even better. Nothing else will bring as much natural light into the space. Just make sure they're installed correctly.

Skylights wouldn’t have worked for us as well. We didn’t want that big hole in the roof for each of them. We live near huge Douglas Fir trees & didn’t want to have to deal with cleaning the skylight glass. We have the fir tree debris blown off of our huge hipped style roof every time high winds blow from the east - the direction those trees are from us. So, the Solatubes were absolutely the best solution for us. Skylights can let sun shine in which may be a problem with fading of fabrics, floors etc. Solatubes don’t have that issue. Only the light comes in.