Color discrepancy between app and browser (Mac Version)

I turned off the background I had on in the design I'm working on (just because it repeats when using Snag-It and screenshotting the whole page) and changed the background color to a semi-transparent color (just because that's one I had handy at the moment lol) and I noticed that it doesn't show up correctly in the app as it does in the browser (Chrome). I've uploaded a screenshot so you can see what I mean.

The Color Used is rgba(36,49,112,0.4)