The technique of blue and purple painting layers were analyzed on the example of selected panel paintings of the mid-16th to the end of the 18th century from the Gdask painting workshops. Paintings are the property of the church and the museums of Gdask and Pelplin (Poland). Searching studies of the selected painting layers and of the samples were performed to characterize the pigments present in the individual blue and purple painting layers and the pictorial techniques. Samples were obtained from painting and ground layers. The blue pigments identified in Gdasks' paintings of the 16th and 17th century were natural azurite, smalt, and natural ultramarine, and of the 18th century, the only one blue pigment was organic indigo. Purple layers were obtained by adding organic red, lead red, vermilion, and iron oxide red. (c) 2016 Wiley Periodicals, Inc. Col Res Appl, 41, 270-275, 2016