There are many out there and you just have to
search them out. The best way is do a google
search for specifically what you are looking for. It is best to stick with the ones who specialize in mineral makeup for your skin tone. The trick with the deep skin tones for minerals is that there has to be a good balance between teh zinc, titanium and serecite and the other ingredients used for color such as the iron oxides. Too much zinc and titanium will make it weird looking and not enough will leave it lacking in coverage. Basically with minerals the coverage comes from the tianium dioxide and the zinc. They have superb coverage, they are totally opaque. Serecite and talc and other powders aer translucent so there is no coverage. It is a bit tricky to get the deep foundations right. So make sure that where ever you go that you order samples and go out into the daylight with a mirror and look at the samples on your skin. There should not be an obvious difference between your skin color and the makeup. So my dear when you find a company that has your perfect shade let others know.
THe ashyness is not from the whiteners such as zinc or titanium themselves. it would be the iron oxides that are used, meaning the combination of the iron oxides. If a lot of black oxide is used then is is gong to mix with the zinc and titanium and be greyish. It is basics of the color wheel really. So the combinations of shades mixed and the whiteners will give you the color and it is a tricky thing to get the deep shades right. Trial and error...so there is really nothing wrong with using titanium or zinc but it is how you mix it all up.