There is consensus within the research community and practicing UX professionals that color definitely has an impact on how a site or application is perceived by the user (paper discussing design factors).
The Society for Technical Communications published an article in 2011 entitled Color Matters: Color as Trustworthiness Cue in Web Sites. It's likely the closest thing you'll find in published research that attempts to answer your question.
The authors concluded that a blue color scheme was perceived as most trustworthy and black as least trustworthy. The point of the paper was to demonstrate that color does impact trust - but the numbers only show a small difference in user feedback from one scheme to the next.
I too have encountered resistance from stakeholders insisting that the application must be designed to mimic the look, feel, and functionality of competing products. I would bet that similar feelings are driving the desire for a darker color scheme - but instead of just saying that, opinions are being thrown around as if they were facts.
- Review with the team the websites of trusted security providers. Kaspersky, Symantec, Mcafee, and Kali all have light color schemes. Barracuda has dark landing pages but they lighten up quite a bit once you navigate to interior pages. Defcon and Blackhat are as you would imagine.
- Take a few screens and comp them using different schemes - but modify them to ask the user for something sensitive, like a credit card. Use them on one of the cheap user testing sites and ask whether the user trusted the app.
- Make design disputes less about opinion and more about what you can prove (either with research or testing).
- If you can't come to a data-driven conclusion, propose a compromise and instrument the app or feature with analytics to monitor the impact of the decision post-launch. Teams will usually go for this and it will help move the process along.
- If all else fails, and the design team is in a tie that can't be broken, flip a coin. Both options must be equally good if they have an equal amount of support :-)