beautiful color of gem, flaw in gem
玼 centers on the dual nature of a gem's appearance: it can refer to a beautiful, vivid color, or to a visible flaw that mars the gem. The meanings are somewhat contradictory, reflecting either a perfect hue or an imperfection.
玼 combines 王 (jade/gem) with 此, which likely contributes a phonetic element. The exact historical development is uncertain, but the character is associated with describing the quality or color of a gem.
The left side 王 represents a jewel. The right side 此 looks like a comparison or a stop: imagine examining a gem and stopping to notice either its brilliant color or a tiny flaw. The jewel can be stunning or imperfect.
For セイ, picture a gem appraiser saying 'say' when they spot a flaw: 'Say, that's a beautiful color, but there's a flaw here.' The word 'say' cues セイ.