What is the range of possible IP addresses when expressed as decimal and hexadecimal?

I know that there are $2^{32}$ different combinations of IPv4 addresses possible , if expressed in binary.

In decimal notation, they range from $0.0.0.0$ to $255.255.255.255$.

So are there $256^{4}$ possibilities if expressed in decimal?

And $16^{4}$ in hexadecimal?

Thank you.

Note that the $256^4$ figure you obtained is equal to $2^{32}$. In hexadecimal, the addresses range from $00.00.00.00$ to $\text{FF}.\text{FF}.\text{FF}.\text{FF}$, which gives $16^8 = 2^{32}$ possible addresses. To reiterate: the base only determines how you write the addresses, not the numerical values the address has. There are always $2^{32}$ distinct addresses.