Baker CharlotteSometimes showed off a cake that amazingly changed color as it spun around on a plate. Sometimes didn’t offer insight on how she made the cake, but former cake decorator Nyphetamine Blue explained in the comments, “this is not fake it is done by airbrushing the cake from opposite directions using different colors…”. Commentor Filmorth compared the process to painting a car. “It works like chameleon spray on cars. It has several layers of edible paint sprayed on to it from different angles so the color of the cake depends on how you look at it.” But it was Jeremy Barrios who offered the most comprehensive explanation.
the decorator ices the cake and uses a frosting comb to give it a wavy pattern, afterwards using a airbrush machine colors one direction in one color, avoiding to get some on the other side afterwards, they then, turn it on the blank side carefully add the second color, avoiding mixing the two colors. By having a texture on the cake, it makes it easier to do these effects!
No matter how it was done, the optical illusion effect is absolutely amazing.