Simon
I finished the spectroscopic measurements of the colored Sapphire samples from 1600 to 300 nm wavelengths (respective figures are attached).
I measured the transmittance (T) and the reflectance (R) for both blue and green sapphire samples, and calculated the absorbance by 1-R-T = A.
In short, the green samples have the lowest absorbance at 1064 nm wavelength (A = 0.05), while the absorbance of the blue ones ranges from 0.143 to 0.158.