bright white, bright, clear
皦 centers on pure, intense whiteness and the clarity that comes with it: bright white light, something brilliantly clear, or a luminous quality.
皦 combines 白 (white) with 敫, which likely contributes the sound and may relate to light or shining. The exact historical development of 敫 is uncertain.
The left side is 白 (white), and the right side 敫 looks like a radiant sun 日 with rays 攵 and a banner 方. Imagine a brilliant white banner glowing in sunlight: 皦 is bright white and clear.
For キョウ, picture a bright white light shining on a Kyoto temple: Kyoto -> キョウ, and the temple's white walls gleam with clarity.