2D Lights - How to change the color of "darkness"?

Someone else has asked this months ago and they got no answers.

Today I realized that when the scene has spots with no light (dark), my sprites there become RGB(13,13,0) instead of plain black. I would like it to be RGB(0,0,0).

Is there a way to change the color of that darkness?

Edit: It seems that in the editor, darkness is RGB(0,0,0), but in the WebGL build of the same project, the darkness color changes to RGB(13,13,0). This is obviously not intended. Has that happened to anyone else?

Edit2: I made a forum post about it.