L-R: Barry M 129, 143, MAC Purple Rite, Up the Amp, Illamasqua Fetish, MAC Violetta and Style Curve.
Violetta (Perm, PRO) and Style Curve (LE) are both very similar, SC is slightly more red toned and is a cremesheen rather than an Amplified Creme.
Morange (Perm) and Neon Orange (LE and Perm PRO) are also similar both are AC but NO is slightly more red toned.
If you have Violetta, you probably won't need to get SC. If you have Morange or NO you won't really need the other.