Regardless of the airbrush style, make or manufacture, here are some generalized points:
1) There is NO need to completely clean an airbrush (and let it dry) between colors.
We only need to FLUSH the old color out when we're making Drastic color changes and want to avoid the old color from tinting the new color (blue turning our yellow green.....).
We only need to CLEAN when we are changing formulas that are incompatible with each other (extremely rare in the culinary world) OR done for the day OR need to troubleshoot a problem.
2) Reduce major color change time by planning the color sequence of the project.
Follow the color wheel - lighter to darker - and let the colors do some of the blending and layering for us.
For example, start with yellow, then move to blue as the 2 colors overlapping will be green anyway.....
Choosing an Airbrush Style:
1) Pay attention to Needle/Nozzle size. (N/N)
For culinary work, we typically use .3 mm - this is large enough to spray pearls/shimmers/lusters and still spray a resonably fine line.
The larger the N/N, the thicker the fluid it can spray.
2) Have enough air "power" (PSI) available to do the job.
The larger the needle, the thicker the product, the more volume it can spray, the more PSI it will need to spray with.
3) Top Feed (gravity) are generally used for details and small applications.
The top cup allows for lower PSI as the fluid path's "plumbing" is simpler.
The smaller color cup allows for easy color changes for projects that have smaller coverage with frequent color changes.
4) Bottom Feed (siphon) are generally used for larger coverage, with frequent color changes.
Higher PSI is required. Not typically ideal for detail work.
5) Side Feeds - a good "in between" system when needs are generally split 50/50 between Top and Gravity's "sweet spot".