使用Express从localhost获取数据/向其写入数据

I'm trying to create a webapp for a web art class using node (w/ npm) and express. The idea is to have the body of the site be all one color, but anyone can text the site a hexcode/CSS color at a Twilio number and the color of the site will instantly change to that color value. I'm trying to create a webapp for a web art cla