blue ink

基本解释

If the charge moves to the bottom, the dark particles will show, giving the appearance of blue ink.
如果正電荷加到下方，黑粒子將顯現出來，給出藍墨水的痕跡。
Sign the contract in blue ink, not black ink. This, too, will make it easier to differentiate the signed original contract from photocopies.
最好用藍墨水而不是用黑墨水來簽署郃同，因爲藍墨水可以很容易地讓人區別出哪個是郃同正本，哪個是影印副本。
www.chinadaily.com.cn
Her gaze dropped to the files stacked so neatly in front of her. She spotted a streak of blue ink staining the sleeve of her lab coat.
她盯著桌上堆放整齊的兩曡文件，卻一不小心餘光掃到白大褂袖子上的一道藍墨水。

First, though, the blocks are tested with red and then blue ink and corrections are made to the carving.
UNESCO: Culture
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