Green = the safety net, when you join us, the insurance will back you up. As it is a very pleasing colour, you can live life as you please, without too much worries.
Yellow = Shows a little danger, as it is close to red. The insurances will cover your incident no matter how small.
Red = Huge Danger, like accident or something. That insurances will cover huge accidents too.
Lastly, Blue = tranquility, because it is a very calm colour. That the insurances will calm down the incident, and it will be a huge heal to ease the sitaution , no matter for big(red) or small (yellow)