indigo
藍 centers on the deep blue color of indigo, both the dye and the plant it comes from.
藍 combines 艹 (grass/plant) with 監, which likely contributes the sound. It originally referred to the indigo plant used for dyeing.
The top grass radical 艹 hints at a plant, and the bottom 監 looks like a container for dye. Picture indigo leaves being steeped in a vat to produce the deep blue color.
For ラン, imagine a runner wearing indigo shorts: run -> ラン, and the runner's clothes are dyed with indigo.
dyer's knotweed (Persicaria tinctoria, used to produce indigo dye)
mottled spinefoot (Siganus fuscescens); dusky rabbitfish; sandy spinefoot
indigo blue; indigo
indigo dye
temple (esp. large one); monastery
indigo-dyed leather
indigo
complete seven-structured temple compound
deep purple; reddish indigo
synthetic indigo
empty; hollow; bare; vacant; deserted
pelican
Buddhist convent or monastery
pupil excelling his master
surpassing one's master
religious buildings (temples, shrines, pagodas, etc.)
large temple edifice; large temple
natural indigo
lazulite
Brussels sprout