I don't know about the "yellow" grout. Sounds weird to me.

Tile does NOT need to be sealed....grout CAN be sealed although it doesn't make it waterproof....it just makes it eaasier to clean.

The dark ring indicates that the weep holes aren't working. They should have been blocked by pebbles....

What kind of waterproofing was used? A preslope with a liner over it and a final slope before the tile or ONE mudbed with a Surface Applied Membrane such as Kerdi or Hydroban?

We could use some pictures of the work in progress......

Thank You so much for answering. I will post a photo in a day or two of the mess that we intend to redo. Actually, it's not a Kerdi. Our old shower was demoed and then hot-mopped etc. I also learned that if men use this bathroom honey onyx mosaic is not a good choice because of accidental acid stains on the floor near the toilet. I really do appreciate any help you could give.

Rip it out and start over with a better waterproofing system and a more suitable material. It was planned poorly from the beginning.

I agree. Honey Onyx is beautiful, but a poor choice from a maintenance standpoint. Look for a similar tile in a porcelain product....very easy to keep clean......

We have a concrete foundation in our bathroom which was covered by vinyl tiles. My husband tore out the tiles. We want to have Armstrong Alterna vinyl tiles professionally installed. I keep reading that we need a subfloor (from plywood?) put in before the vinyl tiles are installed. Is this true? How thick should the plywood be and does anyone have any tips for us? We are novices, to say the least. Oh, we live in Las Vegas which has extremely low humidity.
Kathy