It seems to me that changing the eye color is an an incredibly minor adjustment compared to the
in Klingon design we've seen. Let's see...
"Errand of Mercy": "Alien Mongol" look with brown-green pancake makeup, short hair, bifurcated eyebrows; all Klingons clean-shaven except for Kor and his lieutenant, who wore goatees (more or less).
"Friday's Child": Completely human-looking, with full beard, short hair.
"The Trouble With Tribbles": Still human-looking; goatees on featured Klingons, but some background Klingons beardless.
"A Private Little War"/third season: Back to the dark makeup and bushy eyebrows; goatees and short hair still standard on males, though some extras in "Day of the Dove" have just mustache or soul patch, and at least one is clean-shaven.
ST:TAS: Stylized version of finalized TOS look. Female Klingon with thinner brows, afro-style hair.
ST:TMP: Major redesign: head bald on top, single massive vertebral ridge extends along middle of head; bridge of nose also ridged. Beards, bushy eyebrows retained. Hair medium-short and backswept.
ST III: Single row of vertebrae replaced with wide bony plate, individualized for each Klingon. Noses now smooth. Long-haired look debuts. Female Klingon (Valkris) has much subtler ridges.
ST:TNG/DS9/VGR/ENT (debuting 1987): Much like ST III design, but restoring TMP-style nose ridges. Female ridges now just as pronounced as male, except in hybrids (and in abortive
female-Klingon design seen briefly in "Hide and Q," with narrow ridges bifurcating full head of hair).
ST V/VI (debuting 1989): Similar to STIII, but with subtler, less protruding forehead plates. Noses smooth. Females again have very subtle ridges, and Chang barely has any. Long hair and various beard designs still standard, though Chang is bald with slight mustache.
STID: The one Klingon we've seen so far has a cranial plate and ridges similar to the previous three designs, though perhaps a bit more bulbous and with subtler ridges. His eyes seem unusually light, though it's hard to be sure. He is bald and clean-shaven, though reports suggest that others have hair. Ears and (by one report) ridges are pierced, adorned with rings.
The Klingon look has been evolving for decades, and this isn't any more radical than the changes we've seen before. It's still just a variation on the basic design template that's been standard since 1984. The only real novelties are the eye color (apparently) and the piercings and masks.
