I also don't understand how using company property justifies ownership of intellectual work. What about using a company pencil should give you the right to any sketches I produce with it?
Up to the value of the paint only. If Leonardo had painted Mona Lisa with stolen colours, no-one would expect the painting itself to be ownership of the paint merchant.
However everything the company does is seen in terms of investment... you invest in machinery and employees so that you can get more back than what you put in.
When you loan from VCs, you can't tell them "you only get back what I loaned". They want a cut of the result.
If you borrow something from the company for your own use, you are in a very real way making use of their investment. Since assumption is you didn't ask, why do you assume they want to give a bank-kind loan, not a VC-kind loan? (In fact, what we are discussing here are employee contracts where it is stipulated that such loans are of the VC variety... If you want to borrow under other terms, make a contract for it...)
A fine at best. Theft is criminal full stop. Civil cases are for slander and other civil offenses.
(At least that how it works in the UK. With regard to the US, I remain astonished at the scene in the West Wing where someone advises Josh Liman to sue the people who shot him.)
I think this is a badly chosen example because it seems that the paint is tangential to the employee employer relationship just an office supply. Perhaps you could refine and clarify your example and it would be stronger?