Hello, I turned on the both stroke and fill option for the material. It seems like the stroke is half transparent and the fill color becomes darker blue where stroke and fill intersects. Also, the stroke does not become solid black. It becomes dark grey. Add images
Blender 2. 8X Fundamentals: Basic 3D Modeling and Look Development, Widhi Muttaqien
Hybrid Cell Shading / Grease Pencil Animation Pipeline Experiment: TroughTheDust - BlenderNation
Help wanted Grease Pencil front view, other view transparent - Animations - Blender Artists Community
Scaled Model Down, Some Grease Pencil Line Art Didn't Scale - Modeling - Blender Artists Community
How to convert a line drawn with a grease pencil into a 3D model.
animation - Why is my ONE grease pencil layer transparent against the background? - Blender Stack Exchange
Bring Your Illustrations to Life with Blender 3D, SouthernShotty3D
Fix Grease pencil depth issue in render & lineart draw over other grease pencil objects
Can see through strokes in blender grease pencil - Blender Stack Exchange