About colours of 17th century Dutch ships: these where not a fixed item. The schipper (captain) of a ship got a certain amount of money to paint his ship in some colour, and he could decide for himself what colour to choose. The bulwarks of these ships where often painted in a typical blue or in a verdigris (with pigments based on copper). The green could therefore be somewhat lighter or somewhat darker.
And to match the exact colour in which the Batavia was painted turned out to be a rather difficult thing - as you can see in the mixture Heinrich mentioned.
As with many things when developing a kit - you are dependent on things which are available in the free market. The Vallejo green was a the colour which came most close to a copper green.
Then some other news on colours: last months it has been quite difficult to achieve all the paint we needed to make the paint sets for the Kolderstok kits (Vallejo is a Spain-based company, and due to corona was not always able to deliver all their colours).
We therefore have decided to develop our own range of colours - based on 17th century pigments. This range contains 18 colours in different tones of white, red, yellow, blue and green, and give the model a very distinctive "old" colour.
We expect to have these sets available beginning of september. Just have a look at Kolderstok.com every now and then