Collection 100,Graphic information,experimenting with format and colour

Once I had a concept to work with, variations came together pretty quickly. Colour, composition and stroke were areas I focused on.

 

The two variations below work really well visually, however as far as representing of a set of data they don't work in terms of legibility. I want the viewer to be able to efficiently differentiate between each group of circles.

 

Simply offsetting one of the columns and rotating the set 45˚ both worked quite well, the latter probably producing a better composition to the poster as a whole.