It’s really really really really really dark red

Then it’s not venta black anymore and will have a glossy coating. Part of what makes venta black venta black is the matte texture of it. Slapping a clear coat on top of that now makes the surface shiny and reflective, so now some of the light isn’t being absorbed by the venta black paint. And now you’ve ruined the point of venta black, and it’s no longer venta black.