The first thing is to get photos of the yarns you are considering into Paint. You can open the program and paste right into it or you can download photos and then edit them in Paint. From Miss Babs' website I was able to just right click on the pictures and them copy them into Paint. They will always land in the upper left corner but you can move them over as long as you do it right away while they are still 'selected'.
I already had a sketch of the shawl drawn up. So next I used the 'Paste from' feature to bring that in. (Click the arrow below 'paste' to see this option.)
Then you use the color picker (looks like a medicine dropper) to pick each color up and the fill with color option (pouring paint can) to place each color in the sketch. You may have to play around with the best spot to pick the color up on the photo.
Because I want to use a light color for the CC, I changed the background so that the edge would show up. You can do ctrl+A to select your whole sketch and move it up to get the photos out of the way once you are happy with it.
These are my sketches for the new gradient sets Miss Babs came up with for this shawl -
and this is the sketch from when I was choosing colors for the prototype -
and this is what the actual shawl looks like -
It's a bit of work to go through this process, but it sure beats deciding halfway through your project that you aren't happy with the colors!