This article presents an original method of implementation of the color set back‐projection algorithm that is one of the most efficient method of automated detection of color regions from an image. The detected regions are then used in the content‐based region query. The query is realized on one or more regions, having into consideration the color feature. The efficiency of the method was studied by means of a number of experiments effectuated with the help of a software system realized for this purpose, on a collection of medical images collected with an endoscope. The new method for the implementation of the algorithm is compared with the traditional one not only from the point of view of the execution time, but also from the point of view of the retrieval process quality.