Receive bitmap from theme depended drawable with attrs

I have some drawables with attributes to match them with selected applications theme. Now I want to create a notification with such drawable and, for this reason, I want to convert it to bitmap. I have tried BitmapFactory and ResourcesCompat.getDrawable, but I still do not receive image, filled with collors. It works like a sharm on resources without any attrs, but wen I have resources with attrs, they just did not pass to the bitmap (or to drawable) for some reason. How to receive drawable with colors from theme manually?