Go minimal
If you're riding it fixed then you should get some cage pedals or straps or go clipless
Then remove the rear brake
Remove all the reflectors
Remove the valve caps
I hate that white saddle but you should ride what saddle is comfortable so if it is then keep it, black would look better though
You should probably add some colour so that it doesn't look like a ghost bike. could be stem spacers, chainring bolts, bottle cage, grips
Some nice tires is the best actual upgrade you can do to it, and they would add a tiny bit of colour. S-works turbo have a nice label on them for example.
honestly it's always going to be a cheap ugly bike, the main thing that will make it look good is being beat the fuck up and covered in scratches.
Or take it the other way and go troll bike and cover it in stickers and garish crap and make an anime girl disc wheel
