CSS :not selector - exclude multiple classes from hover

Question

I'm combining three classes on elements

base, base_green, base_blue  

I'm using this to add hover effect only to base class (without base_green)

.base:not(.base_green):hover {
    background-color: #E2E2E2;
}

How can I achive that with two classes?
meaning that, if element has base base_green or base base_blue, do not add hover effect on it
eg. something like this (doesn't work ofc)

.base:not(.base_green):not(.base_blue):hover {
    background-color: #E2E2E2;
}

EDIT:
Thank you all for answers, my initial solution works fine
I had a typo in that concatenated sausage of :not selectors in my css file
/facepalm

I'll leave question as it is, maybe someone finds it useful

Answer 1

This:

.base:not(.base_green):not(.base_blue):hover {
    background-color: #E2E2E2;
}

works perfectly fine if thrown in a JSFiddle

Tested with the following HTML:

<div class="base base_green">GREEN</div>
<div class="base base_blue">BLUE</div>
<div class="base base_green base_blue">GREEN & BLUE</div>
<div class="base">BASE</div>