Hi there, does anyone know why when I try to use my calligraphy tool, the strokes do not stay on the page after I try to do them? I can see the strokes while I'm dragging my cursor but they seem to disappear as soon as they come, and I am dragging the cursor while clicking. 

Looking for the same. Lets wait for the experts.

What color is applied to the Calligraphy tool?

Please have a look here: https://inkscape.org/forums/questions/double-lines-when-using-calligraphicbrush-strokes/

The tool you've provides is great. Thanks for sharing this.