Tarte Bombshell is a very cool-toned, very dark plum with a matte finish. It is a limited edition eyeshadow.
Bombshell is a blackened purple with a muted quality to it and a matte finish. It was very pigmented, and there was some excess fall out when applied, but it has a softer, silkier consistency that made it easier to work with (it could have been more blendable, though). See comparison swatches / view dupes.