Old Brains Vs. New Brains

Hi guys,

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I'm beginning to procure some of the newer Tyranid models. I have an extensive army spanning a decent amount of diverse older units. My older models include zoanthropes. I had honed in on how I like the brains to look for them years ago. But, with the addition of the barbgaunts, neurogaunts, and the Norn Duo, THEIR brains on the promotional imaging seems to have a different vibe. With the bright blue glow being the most common. Lore-wise, and design wise, do these newer "brain units" differ in their ability to use psychic abilities or to channel the warp? I'm just curious that as I get into painting these newer units I should come up with a new way to paint their brains when compared to the design of the zoanthropes.

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Thank you all in advance!