I've offered a few OS X beta versions using lightskyblue;
and will offer a few different colors for the release of 2.1.0.
Anyone that can build LibreCAD from source
can use a script to change all the icons in librecad/res/icons.
Just loop through the folder and do a string replacement of #00ff7f
I'll offer my Python script after I add a tkinter GUI.
Attached is the whole folder from the main repository if you want to experiment with InkScape.