I've only used blue but that is because it is the most contrast color to orange. Usually only see red and yellow so didn;t think those would work well - unless you have a black craft pumpkin (which is usually to glossy so the saral rub doesn't stick and smears super easy).
Not an artist, just a dude that has always loved Halloween and carving jack-o-lanterns.
Any color should work really. Shaft got it... blue is only the suggestion because blue is the exact opposite of orange, so it creates the highest contrast.
I swore I replied to this but I must not have hit "submit".
I have the graphite and while it transferred well for me it was a mess. It rubbed all over the 'kin and was a lot harder to wash off. I had black on my 'kins everywhere that year.
I find Saral cheapest on Ebay. I keep checking throughout the year and sometimes can find a really great deal on it. If I need some right away Amazon is my go to place.
"Who is this irresistible creature who has an insatiable love for the dead?"