How did they: make the colour black?

Black is the colour of the land after the flood and is the symbol of the fertility it brings to the land. In Ancient Egypt, the colour was frequently used for eye make-up as well as wall paintings, statues' coatings and tombs. 

Black pigment rarely had the inorganic origin of the Pyrolusite (Manganese dioxide) mineral. Galena (lead sulphide) was used a bit more commonly for cosmetic purposes until it was replaced by carbon black and Kohl sticks. All the mineral ores were simply ground to produce the pigment, whereas Kohl was only soot from burning plant. The most common pigment of all is carbon black. It was extracted from organic charcoal. Charcoal was made mostly from burned plant material. Pyrolusite appears to have been much less robust than carbon black. 

When it comes to coatings on statues and coffins, black was made with bitumen or heated-till-blackened pistacia resin (yellow mastic). The resin was either used as both the pigment and the binding material simultaneously or bitumen was sometimes added as the pigment to give deeper blacks. 

Sources:

David A. Scott, A review of Ancient Egyptian pigments and cosmetics.