TintByDistance

//By Cale Bradbury (@netgrind)
//glsl shader for tinting based on distance the sample color is from the target color

uniform sampler2D tex0; //input texture
varying vec2 tcoord;    //coordinate of sample
uniform vec4 color; //color to show
uniform float dist; //controls how close to the color is shown

void main() {
    vec4 c = texture2D(tex0,tcoord);        //sample texture
    gl_FragColor = c*(1-distance(c,color)*dist);    //tint sample color based on distance it is from the target color
}