ISO NUMBER@1 deals exclusively with saffron and establishes four empirical colour intensity grades : IV -LRB- poorest -RRB- , III , II , and I -LRB- finest quality -RRB- .

It establishes four empirical grades of colour intensity : IV -LRB- poorest -RRB- , III , II , and I -LRB- finest quality -RRB- .
