Shades of gray...
I needed to get rid of this B&W screen, it had become a question of sanity :)
So I decided to go for a break with the AY-3-8192 (sound) emulation, and get back to the graphics code for a while.
After playing a bit with OpenGL (switching to the JSR-231 version of JOGL in the process) and overlay pictures, some basic overlay implementation brought colors to the screen.
Of course, the rendering still needs a lot of tweaking, but for what I've spent on it I'm rather satisfied with the result, and wanted to share some snapshots :