The blue quarter circle is a symbol for Lake Michigan which our whole county is built around, in the color of Chicago blue. The red 6-sided star is a symbol for Chicago which is the main part of Cook County. The six-sided star is a main feature of the flag of Chicago as well. The green stripes represent the many forrest preserves located throughout Cook County. The yellow stripes represent the counties beaches which are a big attraction. Yellow is also one of the counties colors.