Alright, so, this is absolutely killing me. I'm looking

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84KB, 416x670px

Alright, so, this is absolutely killing me.

I'm looking for (the name of) a book I read when I was small'ish - back in the mid 1990's, I guess.

It reminded me a lot of Watership Down, in that the protagonists, as well as the antagonists, of the story were anthropomorphized animals, and the tone of the story was 'dark'.
A peaceful forest settlement of animals was 'invaded' by white/silvery monkeys/gorillas, who had fantastic ideas/technology. Just that, as time went on, these white or silvery monkeys/gorillas effectively enslaved the population, through violent means as well as through dependency. (Colonialism ho.) The book had a sad or bad ending - no freedom to be had for the forest animals.

What may be making this harder (for me; perhaps someone can draw parallels and realize what the original story is) is that I read the book in Dutch. It may even be by a Dutch author and not internationally translated... If so, I'm out of luck.

I've searched for years. Literally every few months tried searching again, but I've always come up empty-handed.

Does this story ring any bells for anyone? I'd be eternally grateful!