Your first two steps are spot on, but then step three could simply be to add a large buffer for each capital and use some and/or/nor/xor (I’d have to look up to be certain) rules to have the buffer zones not overlap, but end where touching. Apply a color scheme and you’re in business.
If the OP is using GIS, it can be even easier.
Your first two steps are spot on, but then step three could simply be to add a large buffer for each capital and use some and/or/nor/xor (I’d have to look up to be certain) rules to have the buffer zones not overlap, but end where touching. Apply a color scheme and you’re in business.