The rundown is this, Clement recently made a list of proposed todo items for Grease Pencil to speed up the drawing code and consequently create vast improvements in the performance. Antonio is now working on those items to make the new 2D suite really shine.
https://developer.blender.org/rB680f8039ebd5419a1aca18c7d0b291ed1b1e4bdc
So if you’ve been having trouble with a bunch of objects on the screen, the new builds should start making everything a lot more usable.
so that’s why when u try changing stroke/fill colors, it crashes…so we should wait after changes to report the crashe!!!
Currently Grease pencil creation is not working in 2.8 branch.
I confirm crashes at color changes and invisible strokes if you try to draw with Red, Blue, Green materials.
Anything that is not Black has an issue.
The devs. are on top of these issues.
https://lists.blender.org/pipermail/bf-blender-cvs/2018-November/116401.html
So they know that the stability of Grease Pencil took a bit of a hit, just wait a couple days or use the latest stable build you have.