Petri Picnic

A six-dose mutation puzzle: form connected groups of four. Surviving microbes change color every two doses, while vitamins keep their color. Select a color and tap an empty square. Orthogonally connected groups of four or more clear when a vitamin is added. Two doses of each color are available. Every second placement cycles surviving microbes red to blue to yellow to red, after checking the placed group. Vitamins do not mutate. Undo restores colors, stock and mutation timing. This is a fictional puzzle, not medical guidance.