Very difficult to say without making your own samples, not just the mortar but panels with the chosen bricks. I was going for lime but switched to white cement which achieved a very similar result, albeit a completely different colour scheme to what you are trying to achieve. I used the brick manufacturers tool as a starting point, was surprised how different the bricks look even with slight changes in joint colour https://nsxpwebapp.nelissen.be/publicconfigurator/?_gl=1*1fxpchc*_gcl_au*MzcxNDA4OTIwLjE3Njc2ODI0NDE.#