After long deliberation and thanks to your valuable feedback, I have tried another variation on Vigil’s cover:

From the blog of Nicholas C. Rossis, author of science fiction, the Pearseus epic fantasy series and children's books

The background color is close to #3, only a tad lighter, in order to work with the text’s red hues.

However, so many of you liked #1, that I’ve decided to use it for the last book in the series, currently being penned (since I still have no name for it, I thought it’d be fine if I left it with Vigil for now).

From the blog of Nicholas C. Rossis, author of science fiction, the Pearseus epic fantasy series and children's books

This ties in with the plot, as the covers have progressively been getting darker, along with the story. In Vigil, however, several the subplots gradually get resolved. That’s also why the scales, after almost falling apart in Mad Water, are slowly becoming more solid here.

The final book sees the resolution of the overall story arc. As such, it makes sense that the colors get even lighter. Even if it does resemble Schism, this is not a bad thing, as in a sense the story has come full circle.

Again, a big thank-you to everyone who helped me with this! You guys are the best 🙂