/usr/share/gwyddion/glmaterials/Emerald is in gwyddion-common 2.47-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 | Gwyddion resource GwyGLMaterial
0.0215 0.1745 0.0215 1.0
0.07568 0.61424 0.07568 1.0
0.633 0.727811 0.633 1.0
0.0 0.0 0.0 1.0
0.6
|