dye, color, paint, stain, print
染 centers on applying color to something so it soaks in: dyeing fabric, painting a surface, staining an object, or printing with ink. The idea is always about color penetrating and changing the material.
染 combines 氵 (water) with 木 (tree) and 九, suggesting the process of dyeing cloth using water and plant-based dyes. The exact role of 九 is uncertain, but it may have contributed a phonetic element.
The top part 氿 looks like water 氵 and a number nine 九, and below is a tree 木. Imagine dipping cloth into a vat of water mixed with dye from nine different trees, soaking it until the color stains deeply.
For セン, picture a dyeing master carefully counting sen (千, one thousand) drops of color into the water, making sure the shade is perfect: 千 -> セン, and the dye soaks into the cloth.
infection; contagion; becoming infected
pollution; contamination
stain; spot; smudge; blot; smear; blotch
dyeing; printing
familiarity; intimacy; acquaintance
to be dyed
familiar; well-known; regular (e.g. customer); favourite; favorite
dyeing
contagion; infection
to become familiar with; to get used to; to become accustomed to; to adapt oneself to; to become attached to; to become friendly with
to dye; to colour; to color
to soak (into); to permeate; to seep (in); to penetrate; to pierce
dye; dyestuff; coloring agent
Yoshino cherry (Prunus yedoensis)
being drawn to something one loves; amorous passion
indigo dye
dyeing and weaving
bloodstained
hair dye (for graying hair)
to penetrate; to pervade; to spread