As a Tradition, Rolex used to Apply Green Colour on their watches, Watch boxes, warranty Certificates and and Catalogue.
This is a 1982 Rolex Day Date with Green Rolex enamel Dial... 18Ct Solid Gold with rubies and Diamonds on the bezel. Looks like new!
This kind of enamel Dial surface will have crack lines after 15-20 years. This Sample does also have some lines of micro crack on the dial. That may be due to the enamel process has some impurity or may be the delimination between the enamel and the dial base material after years of Temperature cycles.
The cause of the crack line is unknown to me. Anyway, this crack lines is the reflection of natural aging of this Beautiful Rolex.
Seems there is no perfect enamel dial. I am not sure if the new enamel process is improved or not?