// https://www.shadertoy.com/new

void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
    vec2 uv = fragCoord/iResolution.xy;

    vec3 col = 0.5 + 0.5*cos(iTime+uv.xyx+vec3(0,2,4));

    fragColor = vec4(col,1.0);
}