The animation uses a "hot metal" colour scale that begins at dark red and progresses through orange and yellow to white at the highest levels of activity.
影片里用色线标出了活动等级：由深红开始，逐步过渡桔红，再到黄色，进而显成白色这一最高等级。
2
Intermediate yellow fever: In humid or semi-humid parts of Africa, small-scale epidemics occur.
中间型黄热病：在非洲潮湿或半潮湿地区，时而发生小规模流行病。
3
But as the scale grows and the demand for biofuel crops seems to be infinite, we're seeing some negative effects and we need to hold up a yellow light.