The assignment:  Use at least 4 different hues (colors) of blue in a composition that includes architecture.  Architecture is defined as anything manmade.

Purpose assignment:  To learn more about blue hues including value (light and dark)  and chroma (intensity or strength of color).

Consider:  Making a color Chart of each hue (color) before making your painting.  Begin with the strongest chroma of blue, then add white, black and gray to vary the value and chroma.

Study of Roman Ruins using 4 different blue hues by Ginger Dean