Type of mortar for brick facade?

[Per_Eriksson]

Trying to find out what type of mortar my brick facade is joined with as I want to make some changes that I want to be as invisible as possible.

A mason suspected lime mortar based on the year of construction, 1956.

Built a support for a windowsill with plaster mortar C from Combimix but it becomes much lighter/grayer http://combimix.com/se/produkter/produktsortiment/fasad/putsbruk/putsbruk-cs-ii-hand-info

And pure lime mortar seems to become even lighter towards the whitish direction.

 

[peternicklas]

It's not easy. Our grout today is turning light blue/gray somewhat. It was originally black. Sun and water change a lot. Don't you have a way to remove and expose grout that hasn't been exposed to sun and water?