Or bugs, which leave these red or blue stains.

或者虫子，会留下些红色或色污渍。

He wiped away the blue stain above his lip with the back of his arm, then let out the tiniest burp.

他用胳膊背擦去嘴唇上色污渍， 然后打了个最小嗝。

Here's a classic histology image of cirrhotic tissue, this clump of cells in the middle is the regenerative nodule, and these blue stains surrounding it are the bands of protein from the process of fibrosis.

张典型肝硬化组织组织学图像，中间圈出部分堆细胞就再生结节，包围再生结节色区域肝脏纤维化过程中形成蛋白质束。