Yeah, lots of white pigment - lots. 4x is a good starting point. Take it from there.
For orotones, I've so far always used gelatin with an easy-to-disperse 'gold' pigment, which really is mica (with maybe a little iron oxide?) with a truckload of dispersants added to it. Works surprisingly well. Make a gel with this pigment and then pour it like you'd pour a collodion wet plate. Again, it takes a lot of pigment to make a layer with sufficient covering power.
For orotones, I've so far always used gelatin with an easy-to-disperse 'gold' pigment, which really is mica (with maybe a little iron oxide?) with a truckload of dispersants added to it. Works surprisingly well. Make a gel with this pigment and then pour it like you'd pour a collodion wet plate. Again, it takes a lot of pigment to make a layer with sufficient covering power.