I'm a big fan of black as both a statement and accents (e.g. high gloss kitchen bench tops and splash backs, matte black main vanity and floor tiles, lounge, Art Deco sideboard etc). It seems to collect and show dust on the floor more than most, and can suck a lot of light depending on its location and application. Why not 'test drive' your black flooring idea (cheaply) with some wide black gardening plastic from a hardware store for a few weeks before committing to an expensive and potentially irreversible step. The plastic can always be used as a drop sheet later! You may find that having your black in furniture (such as Japanned table or sideboard) and accessories, together with the odd touch of jarrah, may be the look and colour balance you seek.

Another option is to paint the floor boards, Feast Watson has a floor paint and there are many Dulux colours to choose from. I would think, depending what is on the floorboards, that hopefully a light sand and three coats of paint. 7 days curing time.

They might be Baltic Pine? What is the age of the house? You could do a google image search for "Baltic pine floorboards" and "cypress pine floorboards" see what the grain and knots look like- do either match with your boards? Yes, you can make them look more like the white washed photo. We have cypress pine boards and recently had them sanded and refinished with Bona White as we wanted to ensure they had no yellowy or orange tinge and make them look more contemporary. They were very orange from the original oil based varnish. We're very happy with them, although we only had one coat of white and it may not have shown up as well as our sample boards. Two coats would have made them more white. The Bona White system was chosen because it is low VOC water based, so doesn't have a strong odour, compared with solvents. Sample boards, showing two coats of Bona White top section, one coat of Bona White bottom section and a varnished board with no stain. This is on Cypress floorboards.

I like the 525 Coastal Gum in your last pic. It's light but has that ever so slight red in it that goes with the terracotta tiles, although it could just be the pic and lighting etc. But I do prefer it. Or I was going for the 550 before that. You definitely need to stick with the lighter/or oak look finish I think. Dark is way overrated and a bugger to keep clean. It shows up so much in the sunlight and yet I don't even have all that dark floors. Mine is more like a merbau look laminate and it shows up so much dust and dirt (I'm on acreage with a gravel driveway though!) But my parent's have a spotted gum engineered timber flooring with a shiny finish and it is sooooooo much nicer. So definitely stick with the lighter oak finish :)