So... Popculture has traditionally attributed this flag to the IRL Stede Bonnet, depicng a horizontal bone with a skull on top of it, small heart on the right and small dagger on the left:
BUT there are no primary sources for Bonnet ever using this kind of flag. The same goes for Blackbeard's flag. (actually, the symbolism depicted in it would have made no sense for people at the time, which heavily suggests the flag has been designed way after the fact) These iconic flag designs are very likely fictional, and it's more probable that both Bonnet and Edward Teach used a standard, death's head flag and a plain red flag for intimidation.
Did this historical detail stop me from making pride flag edits of them? Hell no!
Have a punch of rainbow pirate flags! You can use them however you like. Crediting me is optional.
These are also super easy to edit in GIMP, just use color to alpha from colors menu and choose either white (default) or black and add a flag of your choosing to the layer below. Go wild mateys!
here's edit of the more historically accurate death head flag that was probably used both by Bonnet and Teach (and other pirates)