Circles round the outer edge

i knew that i wanted to soften the outer edge of my main circle espescially since the design was contained within the white of the page and felt that it would look too bland if i just left it. softening the edges would simultaneously introduce a little texture around the outer edge which would contrast again the fill of the circle.
i created a layer which i placed at the bottom and used the elliptical tool to create two circles slightly larger than the main one. i then applied the chalk brush  to each ( a brush style i really liked and felt would be a bolder dappled texture than previously used) and created a light blue ring and a grey. origionally i had planned to just use grey but i thought that there wasnt enough of the blue tone in the poster which would be an ideal contrast to the thick fill of orange.

rings with basic fill- i think it looks really good - has also reminded me that i need to fill the bottom of the buildings with the darker grey since i think that theres more of a contrast with the darker tone.