If the ISP is broken or not depends on what parts of the interface the clients require.

If there is just one client as in your example, and it requires all of the interface methods, then this is no ISP violation.

Moreover, it could perfectly make sense to have a color "indefinite", which can be the return value for pets like fish. This can be a valid design decision to keep things simple and does not violate any SOLID principle.

Whether the ISP is broken or not depends on what parts of the interface the clients require.

If there is just one client as in your example, and it requires all of the interface methods, then this is no ISP violation.

Moreover, it could perfectly make sense to have a color "indefinite", which can be the return value for pets like fish. This can be a valid design decision to keep things simple and does not violate any SOLID principle.

If the ISP is broken or not depends on what the clients require.

If there is just one client as in your example, and it requires all of the interface methods, then this is no ISP violation.

Moreover, it could perfectly make sense to have a color "indefinite", which can be the return value for pets like fish. This can be a valid design decision to keep things simple and does not violate any SOLID principle.

If the ISP is broken or not depends on what parts of the interface the clients require.

If there is just one client as in your example, and it requires all of the interface methods, then this is no ISP violation.

Moreover, it could perfectly make sense to have a color "indefinite", which can be the return value for pets like fish. This can be a valid design decision to keep things simple and does not violate any SOLID principle.