And as evident from humans' tendency to turn red when angry, aroused or upset, such color recognition assists visual communication, too.
而从我们人类的脸在愤怒、兴奋或高兴时也会变红这一点来看，对这种颜色的识别对视觉交流也有辅助作用。
2
A visual indicator shows if the collection has ended successfully or failed (the progress bar is green when collection is completed with no errors, or red when it fails).
When melamine is present, the color of the solution changes from red to blue within seconds and can be measured both by visual inspection and spectrophotometry.