A bill has been proposed in California to ban ICE agents and other law enforcement officers from wearing masks on the job, but it is not yet law and does not currently require all ICE agents in California to remove their masks.
All ICE agents in California have to remove their masks!

FactVerify
Source: factverify.com
What the Evidence Shows
The claim states that all ICE agents in California have to remove their masks. The search results indicate that there is a proposed California Senate Bill 627 aiming to prohibit law enforcement officers, including ICE agents, from wearing masks while on duty. This proposal is a response to concerns about ICE agents covering their faces to avoid identification and accountability.
However, this bill is still in the proposal stage and has not been enacted into law. Therefore, currently, there is no legal requirement for all ICE agents in California to remove their masks.
Additionally, there are arguments and debates about whether the state has the authority to impose such restrictions on federal agents. Thus, while the proposal exists and could lead to such a requirement if passed, the claim that all ICE agents must remove their masks now is misleading because it implies an existing mandate rather than a proposed one.