Lime putty and water are taken in equal amounts by volume, to begin the process of Lime formation. The mixture obtained by adding these two will have a specific consistency which can be altered by adding more water. The end goal of this step should be to get a paint mixture which has a thin consistency and can be coated easily. As the natural colour of Limestone is white, this solution will have a creamy white colour. If you desire to make a coloured paints, natural pigments are used which can be added to create practically any desired colour. 

If you choose to make a coloured Lime paint, then mix the pigment with lukewarm water creating a paste. This paste should have all of the pigment and water mixed completely. Once this paste is ready, add it to the initial lime paint. A ratio of 10 to 1 is advised for lime paint and pigment paste. Pigment in greater concentration can alter the structure and change the lime mortar. 

Keep in mind that Lime paints are dark when applied and become lighter in appearance after drying. It will be the same if the lime paint is pigmented, so doing a quick test before applying multiple coats is important. 

If you want to make quick lime you must be careful. This reaction is highly exothermic, releasing a large amount of heat as quicklime is mixed with water.
The chemical reaction in this method is violent, therefore, use a suitable container. It is very important to take care of yourself by wearing a protective suit with goggles so that your entire skin is covered and there are no risks of spilling the paint on yourself.  
Making lime with putty is much safer as there are no chemical reactions that happen after, so there are less chances of spilling it. Contact with the lime paint itself is also harmful due to its alkalinity. Lime has the tendency of settling down at the button, therefore, it is important to keep mixing it while applying the coats.