epoxy grout

Hi All, I am in the middle of tiling an outdoor patio and for the outdoor steps I need to create a mitre joint along the full length of a 120cm tile to for an L shaped lip (nose). My plan is to use a coloured epoxy to glue the 2 piece together and then use an epoxy grout to finish. What do...

When I retiled my bathroom, I used Mapei epoxy grout in a mid grey colour. At the bottom of the tiling up from the tray, some of the grout had a light yellow tinge to it. Does anyone know how to clean this? Is it possible to remove. All the tiles halfway up, to the ceiling are still the...