Coloring, Color Scheme, Makeup
noun, verbal noun
This is the noun version of the kanji and has the same meaning as well: coloring.
いろどり
The reading has いろ (like 色) in it, then a ど, so think about an 色 dog, running around coloring things, because that's what an 色 dog does.
父の弁当は、彩りについて全く考慮がされておらず、全部茶色だったので嫌でしたね。
I didn’t like my dad’s bento because he never really took coloring into account and all of it was brown.