Previously in Blender 2.7x we had the option to enable "Texture Solid" in the Viewport shading options. This would display the currently applied texture on the objects but also the active vertex colors.
While this option got transitioned to Blender 2.8, it only did for previewing textures. In the new viewport shading options there is still no option to display all active vertex colors on each object.
This means, unless a Material setup in Eevee is used to display only the active Vcolors, there is no way to do this in Blender 2.8.
Adding "VColor" to the "Color" options in the Shading Popup would fix this.
Preferably the option should be available for all shading modes including MatCap.