How to convert blurry edges to be one of the colors it is blurred between?

I have an image with a number of different colored polygons. Each polygon is intended to be a solid color, but the edges of each are softened and blurred between the colors (e.g., the pixels between a blue and red polygons are purplish). I was wondering if there is a way to convert these edge pixels in Photoshop to one of the colors they are intending to transition between. Here’s a snap shot of the image