In this paper, we present a new series of arylidene-imidazolones with a structural motif of Green Fluorescent Protein chromophore with a pronounced solvent-dependent FQY variation. The identified structure-activity patterns made possible creation of a series of fluorogenic dyes with various positions of spectral maxima and Stokes shift. The developed dyes are cell-permeable and can be used for selective staining of the endoplasmic reticullum in living eukaryotic cells.