This little script was inspired by "GIMP tutorial - advanced color correction using sample point and curves" which nicely describes a method to get the color balance of a drawable right.
It expects an active path. If it's not there it exits unceremoniously.
The average RGB values of a 5 pixel radius area around the points in the path are taken and from these color adjustment curves are invoked with the aim to equalize them and thereby get the color balance right.
I made a small python script, similar to a details-enhancement-procedure described here: http://registry.gimp.org/node/27945
Vivid light blend mode is implemented using the color dodge and color burn technique. Selective Gaussian Blur is used instead "Surface Blur" so it works without G'MIC dependencies. Take care of the Gaussian Radius since high values / big images make Gimps Selective Gaussian Blur a VERY time consuming operation.