That got me thinking... why not??? So I bought a package of plain white cotton Granny Panties and use those. And because they're white, I can soak them in peroxide or bleach as necessary without "worrying" about ruining them.
Others have said that they like black/dark for that week because they don't show stray stains.
So do you have special period panties? And special or regular, do you prefer light or dark?