#version 100 precision mediump float; // Input vertex attributes (from fragment shader) varying vec2 fragTexCoord; varying float height; void main() { vec4 darkblue = vec4(0.0, 0.13, 0.18, 1.0); vec4 lightblue = vec4(1.0, 1.0, 1.0, 1.0); // Interpolate between two colors based on height vec4 finalColor = mix(darkblue, lightblue, height); gl_FragColor = finalColor; }