What color to choose as "danger" if the main color of my app is red

I'm having this question wrapped around my head for quite some time. The thing is that my main application has a red color theme. And for just cancel buttons I used to use just gray colors but now that I need a "danger" color... What should I use? Purple? Orange? Using the red again is awkward, maybe a darker red?

PD: I cannot use blue because it's our competitors color.