I would paint it all white to brighten/freshen it up.

Get rid of that yellow glow.

You've got plenty of contrast with the tub, tile, floor, and vanity.

Remove the shell decor and hang a simple white base shower curtain and save your $ for a total redo. Start gathering inspiration for your new bath.

There is a product you can paint over the tub and tiles that is pretty long lasting (until you decide to replace), the product is called Ekopel 2k, they have YouTube videos if you'd like to see how it is used. Otherwise I'd try a neutral white and a fun shower curtain for starters. Also brighter light bulbs. What is your current budget?

Listen to Lyn. White walls will look great with your tub that appears to be the same color as the toilet. Unless you have painted wood cabinets before, don’t try. Done correctly it is a multi-step process for experts. If the use a brighter white for the trim and the door, you can paint the mirror frame that brighter white. Unlike Lyn, I would do a shower curtain that has beige, white, and a third color - perhaps a predominant color from an adjacent room. Let the style of the curtain reflect the general style of the rest of the house - a traditional print, a bright modern pattern - whatever would make the bathroom blend with the nearby rooms. I just checked the Target website, for example, and they have many styles and colors for under $25. Don’t be afraid to put something like a framed print or a framed photo of a favorite location that you would use in another room.

It’s really not so bad. I’d focus on lighting and paint for now. And save save save ...
maybe blues would work in here. Try sampling a bunch of colors that you like. Maybe even a textured wallpaper.

You could do a removable wallpaper. I could see something like this. With maybe a simple white + gold shower curtain.

https://society6.com/product/gold-lines-1139392_shower-curtain?sku=s6-6310465p34a35v287&c_kid=s6-6310465p34a35v287&g_adgroupid=72197345016&g_campaign=%5BNB%5D_1027_US_%5BPLA%5D_MOB_Bed_Bath_Shower_Curtains&utm_term=&utm_source=GOOGLE&g_merchantid=7992249&campaign=%5BNB%5D_1027_US_%5BPLA%5D_MOB_Bed_Bath_Shower_Curtains&utm_medium=cpc&g_adid=355661762300&adgroup=Bed+%26+Bath+-+Shower+Curtains+-+NewPT&g_productid=s6-6310465p34a35v287&g_adtype=pla&g_ifcreative=&g_partition=775284537981&g_campaignid=1555992929&g_ifproduct=product&g_network=g&g_acctid=521-729-4540&g_keyword=&g_keywordid=aud-439427477236:pla-775284537981&g_productchannel=online&gclid=CjwKCAjwzMeFBhBwEiwAzwS8zEtnqLBgTbWCHbpo-7yzfNzLTOGvsRv1pDw7-QgAwRt2MJ6-v-ybJBoCwyAQAvD_BwE&gclsrc=aw.ds

As another idea: this shower curtain, w/ maybe a blue paint on walls.

https://www.overstock.com/Bedding-Bath/Shower-Curtains/29969/cat.html?featuredproduct=30064918&featuredoption=53703728&kid=9553000357392&ci_src=17588969&ci_sku=34959407-000-000&cnc=US&guid=03303151-e40a-4ce6-9454-bd4a41f05240&sponsoredproductid=23180783

Just want to add that you can try both of the above shower curtains with the paint that is already on your bathroom walls - looks like a gold color, and that color works in the space. The lighting in your pics is not good. But that current wall color is fine.

You could really keep it simple... Black framed mirror, some black and white art, new light fixtures, new faucet. The current wood vanity also works.

https://www.lampsplus.com/products/george-kovacs-alluria-24-inchw-black-and-gold-3-light-bath-light__56h30.html

https://www.lampsplus.com/products/possini-euro-wrapped-wire-22-inch-wide-gold-vanity-bath-light__63d27.html

I would be inclined to first have that outlet moved closer to the mirror or if there's an outlet on the right of the sink then get rid of the one above the toilet, but make sure the outlet is GFI. If budget allows replace light fixture with an updated look, maybe only 2-3 bulbs that compliments your faucet finish. Then paint the ceiling and walls a nice white so you can envision other colors to add with accessories (shower curtain, towels, etc.) Once the room is white, you may like the vanity as is, maybe just update the knobs.

By all means, try out some samples in the space. But I don’t think the whites are the best option.

The ivory tone directly above is a bit better than the first brighter white - but you would be better off going further into the beige family, I think. Not whites. Just my opinion.

If you like grey, I think a grey would actually work better than a white.

https://www.wayfair.com/bed-bath/pdp/17-stories-jedrek-abstract-single-shower-curtain-w004512829.html?piid=

https://www.zazzle.com/ornamental_damask_art_i_black_white_greys_gold_shower_curtain-256644723827743121

A neighbor had a curtain made long to cover the tub completely. I think going creamyvwith the paint and keeping the shower curtain closed will be a good fix for duration.

Do not paint the tub! The previous owner of our condo had the shower tiles , walls and floor, painted. Started peeling immediately! What a mess. The renovation started a couple of weeks ago. Buh bye nasty peeling shower!