With all due respect I think you need to research and educate yourself first on what different filters actually do. You are mixing up ND with other 'effects' filters just for starters.
Personally I would first focus on ND filters and how you want to do it. Some use plain ND filters but once you go past .9 your likely to have problems with infra red leaking into your image.(makes the image look red) The solution for most is to either 1. Buy ND filters with built in IR. 2. Use ND and a separate IR filter. 3. Use a variable ND filter which most find you don't need an IR filter but others would argue you still need one.
In a nutshell, post processing is how people are getting the different colors in their footage generally. Filtering 99% of the time is about getting a good neutral image to work with.
Focus on ND filter options would be my advice and educate yourself before you buy anything. The Internet is your friend so don't push me to post a letmegooglethatforyou link.

there ARE other filters but i expect MOST shooters don't use them past ND filtering and it seems you need to prioritise...