[Chameleon] Any idea how I could do the following ?

[Inizan, Sebastien (CDS-VPI)]

I have three layers in my application:

Layer 1- WMS image of the world
Layer 2- Countries in Europe
Layer 3- 1st level admistration (departements) of Countries in europe 

I would like to give the possibility for a user to highlight a
country/countries with different colors. For example a user would like to
draw France with a blue color and Germany with a red color on the map.What
is the best way to do it ? I am not sure how I should start this task ... Is
there any way to modify the map file from chameleon dynamically? 

Thanks,
Seb.