The person who told you that you needed to wear boring and basic pieces, neutral colours and no prints too be a minimalist, has been lying to your face. Of course you can wear all that, you could only wear bright yellow and still be a Minimalism.
Being a minimalist is not about the patterns or the colours, is about only wearing what you love and makes you happy. If you are happy wearing all black and white, that's great, but if you prefer blues and greens, who am I or anyone to say that you can't?
You can take my closet as an example: I mostly like dark colours but I still have my Prints (leopard, stripes, monochromes ) and I still have my pops of colour, like a bright blue bag or my soft pink bag. And I do love finding pieces with a nice twist, like a textured sweater or a two fabric shirt, or even a not so conventional white blouse.
It's all about knowing what works for you and what you feel good wearing. It's about not having pieces in your closet that you will never wear. It's about discovering yourself. And it's about wearing the clothes, not letting the clothes wear YOU.