Thats what I thought, it would be very intimadationg, all that dark color!  You see, I love watercolor, and the white paper!   And letting that white paper show thru in places!      So my first pastel attempt was on the  white wallis, and all that white so hard to cover where you wanted it to be I found it confusing, althought the colors would be so pure---still, lots to think about!   Going to anycolored ground after thinking like a watercolor painter was hard. So i did what I always do----Experiment!   I am not thinking everything I do is frameable, right?  I am just learning!  That made it easier to jump in and do something.  But with the black ground, well, thats so dark, and they say, there is no black in nature!   But we are so use to photos, and seeing the shadows in black---And some artists have learned as well to do this and make it look natural------so after reading the pastel journal and seeing that the negative spaces in the artwork would be left black, not painted on,  I had to try.  And its so interesting.....I encourage you, Mike, to give it some thought.  Mine is not great, not at all, but I tried and will again.   I know you can use this method on some pieces, too!   Heck, its just paper!---and your learning will grow!     Sorry, I can get carried away!