Not sure if this has already been shared here or not. However, today by coincidence when I was playing with Continuum on my 950XL, I found out that launching the Twitter app in Continuum, under Twitter app personalization settings, you can change the app theme to "Light" or "Dark". Once you change it there, it will apply to the "Non-Continuum" view also 
The setting doesn't show under the mobile view, only in the Continuum view, so if you would like to revert back, just go back in Continuum and change it again.
Hope this helps.
The setting doesn't show under the mobile view, only in the Continuum view, so if you would like to revert back, just go back in Continuum and change it again.
Hope this helps.
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