I too had been thinking about making the white elastic black with the ever-useful Sharpie pen (or more accurately, a giant Expo marker). Two TV shows and five black fingers later, I think my son’s armor is much improved.
In addition to my two kids’ costumes, I volunteered to make a Fleur Delacour (in picture 4) dress for their taekwondo instructor. I was hoping that one of the pattern companies would have put together a Harry Potter themed collection with something like striped ties, wizarding cloaks, and uniforms from a visiting girl’s school. No luck though. So, I had to find a “close enough” pattern and work out the rest on my own.
I used Butterick 4607 (which I already had) for the collar and sleeves and Simplicity 3673 for the basic dress. Using the front and back pieces from the shirt, I created the right shaped neck and then self-drafted the rest of the capelet.
It still needs a little scarf, few more buttons and a hem, but I think it came together nicely, and pretty easily too.