Colouring of Venn Diagram
To colour a region in Venn Diagram, say the middle one in violet formed by the arcs k, s and r, we use the following three commands:
G = Point({k, s, r})
G' = G
loc1 = Locus(G', G)
The region loc1 formed by arcs k, s and r is then created and we can now colour it.