The colour for a plant cell's starch grains is typically blue or black when stained with iodine solution. This is due to the formation of a complex between iodine and starch, which results in the ... If only red light shines on it, it will reflect that light. In contrast, a black object appears black because it doesn't reflect any visible wavelengths, so would still appear black . To print on black paper, you can use a white ink printer or a printer that has white ink capabilities. This allows the printer to lay down a layer of white ink before printing the colored image on ... the iodine does not turn the starch black ."The iodine clock reaction is based around the colour change that occurs when iodine reacts with starch, turning from a clear colour to a black -blue ...
