With all these wonderful, deep, dark opaque cobalt-like blues, a head-to-head comparison is in order!
Here we have, from left to right, Effetre 242 Medium Lapis, Effetre 240 Light Lapis, Effetre Earth, and CiM Blue Suede Shoes.
In this photo, on my monitor - and take my word for it when I say that this dark blue is exceedingly hard to photograph and reproduce faithfully - the Light Lapis and the Blue Suede Shoes look like a near match - but in real life - the better match is Medium Lapis and Blue Suede Shoes. The three Effetre Lapis's - Light, Medium and Dark (not shown) tend to very in colour from batch to batch so what is a good match now, may not be true for next year.
Here's a close up of Earth - looking streaky and w/o the colour separation that makes this colour so intriguing.
It's blue - you can't go wrong with bluuuuuuue.