This is one of those cases where there are two hostas with the same name. One is registered and, therefore, the "official" version of H. 'Misty' while the other is a non-registered plant and needs to be renamed to avoid further confusion.
 

Registered in 2019 by Randy Goodwin of Indiana this upright growing, miniature size (2 inches high by 4 inches wide) cultivar is of unidentified parentage. It is a light green hosta with yellow, misted marginal variegation. The leaves are slightly shiny on top, broadly ovate, moderately cupped and slightly folded overall. Medium lavender flowers with darker lavender stripes bloom from late July into August on scapes 6 to 8 inches tall.

The registration materials state: "...Mini with light green to yellow misting."

Hosta Helper will call this plant 'Misty' (Goodwin)

This seedling of H. 'Northern Mystery' is a non-registered cultivar from Jim Schwarz of Jim's Hostas of Iowa (now owned by Uniquely Hostas of Wisconsin) . It is a medium size plant with blue-green foliage that has a misted green and white marginal variegation. The leaves are broadly oblong to ovate in shape, heavily corrugated and have thick substance. Near white flowers bloom in June.

According to The Hostapedia by Mark Zilis (2009), "...has potential as a breeding plant."

Similar cultivars include H. 'Northern Mist'.

Hosta Helper will call this plant 'Misty' (Schwarz)