What color do gram-positive bacteria turn during the gram staining process?

During the gram staining process, gram-positive bacteria turn bluish-purple due to the thick peptidoglycan layer in their cell walls. This thick layer retains the crystal violet stain used in the first step of the gram stain procedure. After the application of iodine, which acts as a mordant to form a complex with the crystal violet, the decolorization step does not remove the dye from the gram-positive bacteria because of this robust peptidoglycan layer. Consequently, when a counterstain, usually safranin, is applied, gram-positive bacteria remain stained in their original bluish-purple color while gram-negative bacteria take up the pinkish-red color from the counterstain. This characteristic feature helps in the identification and classification of bacteria during microbiological studies.