I'm not aware of any actual tutorials for planet zoo apart from creators showing the filters in-game but without showing actual settings. The only video is a generic one where you can activate the freestyle filters with a large choice of settings to tailor your desired look -
Source: https://youtu.be/QF1cYKFFNFM
Personally I wouldn't use filters for actual gameplay since a large amount of color, exposure , and various other settings makes it hard for a universal filter that will work for all biomes, interiors, nightime etc. What I do is use Nvidia Ansel is using the same choice of settings to tailor pictures to look photorealistic - I can tell you every habitat in seperate biomes can take 15 plus minutes of setting up the perfect frame and of course every one needs a totally different setting choice
Of course if you just want to know right now how to activate it - ALT + F3. Press those 2 key together and you get the game filter menu , here you can have 3 seperate filters and you can customise each one for desired environments
