I am not sure what you mean with the "blue screen". Maybe you are referring to the color changes after minimizing or hiding the SheepShaver window that has been a bug for many years in SheepShaver on Intel Macs and that is described with the "Known issues" on the download page and in the setup manual:
Quote:
After minimizing or hiding the SheepShaver window and again bringing it back in view, colors in the window will not be displayed correctly. It can be resolved by forcing the emulator to redraw its screen by changing (and changing back) the color depth setting in Monitors control panel or from the color depth control strip tile.
If you are referring to this issue, try the test build that I posted here recently:
viewtopic.php?f=20&t=9613
