ANSWER
The colour of the Cu-chlorophyllin can vary from blue-green to dark green, depending on the source material (EFSA, 2015).
Reference
EFSA. (2015). Scientific Opinion on re-evaluation of copper complexes of chlorophylls (E 141(i)) and chlorophyllins (E 141(ii)) as food additives. EFSA Journal, 13(6), 4151. https://doi.org/10.2903/j.efsa.2015.4151