Shower grout?

Prior to showering the grout is tan and as the mist spreads the grout gets dark spots that grow into dark lines. I asked here about sealing the grout and was told that it wasn't necessary because of the type of grout used. Don't recall seeing this in the past although it may have been this way. Any thoughts?

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.