Thanks for your answer. Using ‘fill’ solved the problem. Now I am still puzzled why there a difference in treatment between an icon that is retrieved from the list and an icon that is downloaded as svg. Are they not treated the same?
It depends on svg stroke and path attributes directly into certain a given file.
You can read about overwriting color and fill.
For example, if a path element specifies its fill color as an inline attribute, it cannot be overridden by CSS unless targeted directly.
If you wnt use Brick options, svg file have to be properly prepared.