Changing the straps should be fine. You will still have each hook holding up half the weight of the chair. Alternatively, you could change the color of the upper straps.

Easiest - I'd wrap the metal and the upper straps with a thick twine/rope made out of natural fiber. It would provide a natural texture which wouldn't look like it belonged in a S&M dungeon!

I've also seen hanging chairs like that that have the ropes that come off of the chair attached to wood and then brought up to the ceiling:

You could use a closet rod - or a metal pipe industrial style one - just make sure that it will hold the weight.

This one is shaped like yours - but the ropes are kept spread out - they may be attached to a rod like above OR they are just brought together higher up to one common rope and attached to the ceiling OR there is a separate rope for each side attached to the ceiling.

Changing the ropes to be like the one above will also allow more space inside the chair area - having it come to one point - like yours - makes it seem a bit crowded for the person sitting in the chair.

Look at how some porch swings are done + do a search for inside chair swings - you may come up with other ideas. You just need to make sure that whatever is used to attach it to the ceiling is rated for the correct weight needed (if you use two points of attachment = higher weight will be supported) + I assume that there are strong enough boards in your ceiling.

I think you're both on the page i am...I think wrapping the upper straps with black macrame (black is the only color that'll really match i fear), would be the best option. Or like a natural rope to cover up the look of the seatbelts! Ty :)