So weird the background turn black and gray can not see well.
do you know why?
Is this the same as XQuartz gitub issue M1 black background #31?
You appear to using XQuartz with SNAP on a remote linux system. I can display SNAP running on a linux host without issues in an Intel iMac running Catalina, so it is important to mention if you are using Apple Silicon. You should check XQuartz Support and the forums for your linux distro. Does the issue occur with other linux distro applications (xclock, xeyes)?