A truly Blue snake
 

What's the bluest snake you've ever seen in person? The reason I ask is photos can be very deceiving. I'm not talking about a snake with the word "blue" in its common name or a green snake with a hint of turquoise, I'm talking "damn, that snake really is blue!" ;-)

Opheodrys vernalis after they are dead for a bit.

LOL, I've seen them too, but let's stick to snakes that are still breathing...

Well, okay then. =D

The "blue racer" and "buttermilk racer" phenotypes of Coluber constrictor can be kinda blue.
Dendrelaphis cyanochloris is really blue.
Boiga cyanea probably counts because some get really blue heads/chins.
Laticauda laticaudata is a good choice
Blue Thamnophis sirtalis and T. sauritus can be pretty blue.
Calliophis bivirgatus has an orange head to contrast the blue, so is particularly striking

Trying to think of what else shows blue
Oh, Orthriophis taeniurus, some populations show kind of a dusky bluish to the whole body, sometimes just a bright blue head.
I guess Philodryas baroni comes in bluish.
If we're really reaching, some of the blues in Bitis nasicornis and Tropidolaemus wagleri juveniles are pretty neat

I guess I haven't seen all of those with my own eyes but I am drawing a blank on more blue snakes.

Our Buttermilk Racers (Coluber constrictor) here in East Texas are a lovely dark blue with white spots or blotches.
I believe there is a blue coral snake somewhere over in Asia that is brilliant blue.
I have Vietnamese Blue Beauty snakes that are blue with whiteish markings. Their blue is more of a grayish blue, but definitely blue.

San Francisco garters have a beautiful teal/blue color stripe.

Some female Green Tree Pythons become a gorgeous shade of blue while gravid, some maintain the color.

The sea krait (banded sea snake) is blue and black Laticauda colubrine.

I wish more came in blue! :D

Blue phase Baron's Racer.

Hint of blue in a Mangshan viper. Most gorgeous snake I've ever seen.

The coolest actual blue snake I would have to say is the blue green tree python that is solid blue with a white belly.

Eureka!
 

I just scratched my Blue snake itch by getting a pair of Blue Phase Kunashir Island Ratsnakes (Elaphe climacophora)! They have a pattern like a blue and green colored Kingsnake, I've never seen anything like it. They will take until they mature to achieve this coloration, check out one of the breeding adults who fathered the boy!

I had a pair of these climacophora as babies I got this year the city of Minneapolis animal control illegally seized, would not give them back even though they are legal to own in the State of Minnesota and as far as I know destroyed them :angry: