Flooring Tile - grout-vrs -caulk

i have seen (some where in te forum) that a change of plane,such as a shower wall coner joint should be caulked-not grouted.
and that a real tile store will have various colors of caulk.
if this is correct?,where might one find one of these "real tile stores"?
local h/d has no clue

Funny, but HD is a Color Caulk vendor. Through special order, you can get every Custom Building Products, Laticrete, and Mapei color matched caulk in both sanded and non sanded. Sometimes you just need to tell them folks the way it is.

Missed it in your last post where there was no HD reference, but on the subject of thinsets, that garbage they peddle as "premixed thinset" needs to be avoided. Don't be fooled into thinking this bucket-o-failure is in any way thinset.

thanks for the info
i live in a place where 3 d/h's are about 25 minuits away.
i will try the other 2