Wiktionary
n. A very small, blue butterfly, (taxlink Cupido minimus species noshow=1), of the family Lycaenidae
Wikipedia
The small blue (Cupido minimus) is a butterfly in the family Lycaenidae. Despite its common name, it is not particularly blue. The male has some bluish suffusion at the base of its upper wings but is mostly dark brown like the female. The undersides are a silvery grey with small black dots. The male has a bluish tint at the base of its wings similar to the upper side.
Usage examples of "small blue".
She wore a small blue silk necktie, that kept up like a ruff a gauffered cambric collar, and with the movements of her head the lower part of her face gently sunk into the linen or came out from it.
It was a small blue and gold jeweler's box and she looked at it without touching it.
He was quite portly, with a profusion of gray hair, and small blue eyes which age had robbed of much of their brightness but none of their penetration.
He was carrying a small blue gym bag from which protruded a few stray braids of the discarded wig.
The sun pierced with a ray the small blue bubbles of the waves that, breaking, followed each other.
The attacker had found Earth, Q saw the image of the small blue world, not just now but in all moments.