I held a sharp blue edge of steel tightly between thumb and forefinger to each fist.

我每只手的拇指和食指之间都紧紧地捏着一片锋利的蓝钢刀片。

youdao

The reason I'm writing on this, is that I accidentally trapped my left hand in afoldableladder, and now my left hand thumb is completely black and blue and can hardly move itself.

我写此话题的原因是，我的左手不小心被一个折叠式扶梯夹了一下，以至于现在左手的大拇指一片青紫，无法移动。

youdao

They returned to saying they felt "blue" or were "green" with envy or had a "green" thumb.

人们又开始谈论起，某某有点儿蓝色的忧郁，某某嫉妒的眼睛都红了，某某是个绿手指。

youdao

Outside a polling station in the wealthy suburb of Petionville, Zephyr Watson(ph) shows his thumb which was dipped in blue ink when he voted half an hour before.

NPR: Haitians Flock to Vote in National Elections

Each and every smudgy thumb-print was scrutinised: The shaky blue splodge, the inky comet trailing blue splashes, the giant thumbs so large they had somehow voted for two parties rather than one.

BBC: Nigeria's president faces free vote challenge