Legal Question in Real Estate Law in California

Without reading the entire lease there is no way to tell if it is "void" but that is extremely unlikely. At most it might be "voidable." That too is unlikely, however. If the terms of a contract, including a lease, can be determined from the agreement, it is enforceable. If it has a start date, or even year, and then it says it is a one year lease, ending on a particular month, day and time, it is obvious what year it ends in.

Even if it is invalid for some reason, however, the law would then declare that you have a "tenancy at will" which is commonly known as a "month-to-month." If you are in the property and have an agreed rent, that alone is enough to create a tenancy at will between you and the property owner, in the event the lease contract is not enforceable for any reason. So if you withhold rent, the owner and manager would be completely entitled to evict you.

There are two possibilities when a contract or lease is missing an important term such as a termination date. The judge can decide that the contract is void due to uncertainty. Probably more often, however, the judge will try to determine the parties' intent at the time of making the agreement. In your situation, while I don't know what the rest of the lease says, I think it is rather likely that a judge would find some basis to rule that the parties intent was that this be a one-year lease.

The color of the ink used to sign an agreement is of no legal significance.

If there are significant differences between the landlord's copy of the lease and the tenant's copy, this again may require analysis and a ruling by a court as to which is the version originally agreed upon by the parties. You don't say, however, in what respect the versions of the lease differ, nor whether both are signed by both parties, in which case the one bearing the later date would control.

Tenants are allowed to withhold rent in certain circumstances involving a major breach of the lease by the landlord, but you do not mention anything that amounts to even a minor breach by the landlord. Therefore, I'd say that if you withheld rent you'd be evicted and sued.