How can I brighten and bleach the grout in between subway tiles?

Mr. Clean or Spic and Span.

Sealers fill the grout's pores, preventing grime, grit and mold from infiltrating the porous material.

You'll cut future grout-scouring time by half (or more!) if you keep a small squeegee or a clean microfiber cloth near the shower, to quickly wipe down the tiles after you turn off the water. Tell your family to open a window or run the exhaust fan for 10 to 20 minutes after a shower as well, to quickly pull humidity and moisture from the room and help prohibit mold growth on the grout.

Mimi

Here are a couple ideas for you.

https://www.wikihow.life/Whiten-Grout

https://www.mollymaid.com/practically-spotless/2017/september/how-to-clean-white-grout/

Lysol Lime & Rust Remover Toilet Bowl cleaner, comes in a black squirt bottle. Scrub with Scrub Daddy or Mr. Clean Magic Eraser. If stubborn, use a scouring stick to scrub. Once clean, seal.

If you can't get it clean and bright enough, paint with either grout paint or exterior paint. Then seal.

Ideas from other Hometalkers

https://www.hometalk.com/search/posts?filter=clean%20grout

Hello! Heres some other recommended cleaners

The Best Way to Clean Grout-EVER!!! | Hometalk

https://www.hometalk.com/diy/clean/bathroom/the-best-way-to-clean-grout-ever-2295735?expand_all_questions=1

https://www.hometalk.com/diy/clean/floors/homemade-grout-cleaner-recipe-41693881?expand_all_questions=1

https://www.bobvila.com/articles/cleaning-grout/#.Wi6YzKZOmf0

https://www.hometalk.com/search/posts?filter=clean%20grout

Additionally

Painted Tile Grout Refresh with grout pen

https://www.blesserhouse.com/painted-tile-grout-refresh/

Grout cleaning and grout removal and replace it

Here’s a Hometalk link for you to consider. Hope this helps

https://www.hometalk.com/diy/clean/bathroom/how-to-clean-grout-and-install-new-grout-that-won-t-stain-23803774

Hi Mimi - This is the shower cleaner that we use to help keep grout and tiles clean and minimize the mildew - it works on kitchen grout too. I've also included a great article about mold if it's gone that far. Hope this helps! Hugs, Holly

https://pinkfortitude.com/shower-cleaner-diy/

https://pinkfortitude.com/mold-in-the-shower/

PS - We have a FREE eBook with recipes for all of my homemade and all-natural cleaners. You can download it here --> https://pinkfortitude.com/thank#GreenClean

Try a toothbrush and Soft Scrub with bleach

You could paint it

Hi Mimi, here's a product that should help you out,

https://www.youtube.com/watch?v=SngENa8Bawo

You can buy paint pens from your local Big Box stores.

Hydrogen peroxide should lift the yellow without damaging. You can also paint it.

A product called "Grout Refresh/Renew" worked wonders on my grout. You can purchase it in different colors at the big box home improvement stores.

Use a White tile grout paint!

This product is highly recommended and you can get it at Home Depot for around $20.

https://www.homedepot.com/p/Custom-Building-Products-Polyblend-381-Bright-White-8-oz-Grout-Renew-Colorant-GCL381HPT/203498062?irgwc=1&cm_mmc=afl-ir-116548-456723-&clickid=z1j0TBR28xyPRMMX4J0XLQ0rUkFS2CyC0W4b240

Hydrogen peroxide to clean then seal when dry. Make sure to periodically seal to protect it going forward.

I would use Hydrogen Peroxide. To clean your grout, combine one-part 3% hydrogen peroxide and one-part water into a spray bottle. Spray your grout generously and let the solution sit for about 1 hour, to allow time to work. Rinse the area with water and wipe clean with a microfibre cloth.

Hands down, hydrogen peroxide and baking soda. Grab an old toothbrush, a little scrubbing and it’ll be like new again. Be sure to seal it up after.