In All Night Laundry, Bina's blush is clearly visible even when her face is covered in mud.
In And Shine Heaven Now, Jeeves of all people starts developing one when Arthur Hellsing implied that he and Bertie had romantic feelings for each other. It turns into a completely beet red face when Bertie confirms he does.
Bertie: Don't tell me you didn't know!
Charby the Vampirate: When Victor's grandmother tells a surprised Charby that he flirted with her when she was a young woman and was the one to inform inform her that she was pregnant with Victor's father he grows a bright blush across his cheeks and nose.
Happens periodically to Lydia in Cobweb and Stripes, courtesy of Betelgeuse. It's particularly noticeable because she's so pale otherwise.
A rare thing indeed is the male luminescent blush, as displayed here by Tedd and here by Tony. Maybe he's just that girly?
The recently-introduced (in 2014/2015) Ashley has this as a major schtick, which is also coupled with Crush Blush since Elliot is the one typically causing them.
An interesting variation in Homestuck; due to the trolls' differently colored Alien Blood, most trolls' Luminescent Blushes are colors other than red/pink. In this strip, for example, the Blue Blooded Vriska can be seen with blue patches under her eyes.
Seen at least several times in Housepets!, even through the fur covering their faces. Peanut once ended up with his entire face red.
Go to the Khaos Komix archives and click on a page at random. Odds are at least one character will be doing this.
Niels has this happen more than once, notably to 300 when he's either aroused or thoroughly embarrassed with the latter obviously played for comedic effect. Other characters experience this to indicate arousal, and it seems to be a convenient shorthand for sexual attraction because unless the strip demands full-body anatomy, typically for dynamic action, comedic value, or sexy times, the characters are drawn in above-the-belt shots or full-bodied chibis.
In The Noordegraaf Files THEO, (who is male) has this when he's walked in on by a girl while he's shirtless. He hastily covers his chest with a blanket, even though, you know, he's male. Akila also gets this whenever questioned about if her feelings for Katrina are platonic, or something more... intimate. (It's heavily implied she's attracted to Kat, but if they are in a relationship is currently unknown.)
Hannelore and Marigold sometimes react like this when flustered.
Many AnthroPC chassis designs can blush, even without blood vessels. Winslow says that it's ostensibly to help humans empathize with them, but might just be for the cuteness factor.
Sandra on the Rocks gives Zoe a spectacular blush here. As she is far from sweetly naive, this is clearly a sign that Domenico's teasing, and the reminder of her past, have affected her fairly strongly.
Tower of God: Yeon, when Viole put his fingers in her mouth... to free her from the control of a Puppeteer Parasite, of course.
Luminescent Blushes are quite common and prominent in TwoKinds. Each character has had at least once in his or her life.
In The Whiteboard, Sandy shows one of these when the usual crowd is cheering Swampy's having slept with her the night before. Doc comments that it's so intense it's into the infrared.
In Yokoka's Quest, Yokoka, Mao, and Azha feature this at times.
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