There are many ways you can negociate with factory to make it lower if they really want to help and do business with you:
a) you can consider to take factory regular exsited colors for trial orders
b) design your own package material such as manual, color box good enough, for this part you can agree with their MOQ,
but tell factory use part of package materials and keep rest for you, this can reduce main part of cost on your trial order investment
c)or try to use factory regular packaging materials but add some your brand logo on manual, box,etc.
In one word, tell factory how many you really want for trial order, and ask them help to give some workable solution.