Flex按钮左侧为一种颜色，右侧为另一种颜色

I have a Flex button. I need one color on the left and another on the right. I don't need it to be a gradient. Just solid colors. Like green on left & red on right. I really don't want to use an image -- just because it'll probably take me a long time to do it.I have a Flex button. I need one color on the l