This is a set of the following color reference solutions according to PhEur: Colour Reference Solution Y1 - 10mL ampule, Colour Reference Solution Y2 - 10mL ampule, Colour Reference Solution Y3 - 10mL ampule, Colour Reference Solution Y4 - 10mL ampule, Colour Reference Solution Y5 - 10mL ampule, Colour Reference Solution Y6 - 10mL ampule, Colour Reference Solution Y7 - 10mL ampule, Blind sample : Hydrochloric acid solution, 1% in water - 10mL ampule