I am new to baking and I still cannot invest in an airbrush right now. There are these colors Pearl sheen that gives a nice look to "gumpaste" figures or the fondant covered cake. Can I paint it onn using a brush since I dont have any airbrush yet? Will it have the same effect?

Thanks in advance...

Yes, you can paint them on with a brush. Avoid going over the same spot twice or it will leave streaks. It doesn't look as smooth as it would with an airbrush and it ends up taking more color to cover, but it does work.

For a whole cake, dry dusting with luster dust might the same look with an easier application.

Yes, it paints on nicely, but as Texas Rose stated, not as nice as the airnrush would do.

You can also mix pearl / luster dusts with vodka, PGA, or lemon extract and paint with it also. The alcohol evaporates quickly and just leaves the color behind.