forge-1.6.28-SNAPSHOT-r70-496124cc1f
Chromium, the Mutable's (CTM) discard ability is behaving oddly. After activation, CTM's info panel will say CTM has hexproof, however it is still targetable by spells/abilities an opponent controls.
If CTM already had hexproof due to a spell/ability/equipment, after activating the discard ability it will become targetable. If a spell/ability/equipment grants CTM hexproof while it is a 1/1 human, CTM will remain targetable. In both cases it will indicate that it has hexproof.
Hexproof works correctly on CTM so long as the discard effect isn't active, which seems to both grant it and suppress it even if it comes from a source with a later timestamp.
CTM's text in the info panel also displays incorrect information. After activating its discard ability it will retain the "Discard a card:" text, although it cannot be activated. If the ability is activated again while it is already the stack, the text will disappear once the ability has resolved a second time. Lastly, once the effect wears off at end of turn, if it was activated only once and CTM kept the "discard a card:" text, that text will then disappear, although the ability can be activated.