Orange service demands

So I started a new city and I’ve noticed the the service needs are split between and orange/bronze and a red. I understand red is for major demands through not enough services or as simple as a road not being connected but what are the orange indicators for? 
My water, sewage and electricity are more than demand so it’s not down to a lack of services. All my roads are connected to the main services and no matter what I do (buy more or upgrade them) it won’t stop. And I can’t develop anymore till it’s resolved.  Am I being moronic or is there something wrong or that I’m missing? Any help would be great!