Probably felt the red looked too close to blood. That being said, the fact Sanguine Swamp (literally a blood-swamp, with no effort made to mask it) is a card makes that awkward.
And the hand colour because drowning's also something they don't like depicting, so zombieish hands are probably more acceptable than human hands. (I forgot they changed the hand colour too, hence the second post.) They've edited out drowning on at least 1 other card, too. (Butterflyoke.)
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