uniform half4 colorGreen, colorRed;

void main() {
    if (colorGreen.g == 1) {
        sk_FragColor = colorGreen;
    } else if (colorRed.r == 1) {
        if (colorRed.g == 0) {
            sk_FragColor = colorGreen;
        } else {
            sk_FragColor = colorRed;
        }
    } else {
        sk_FragColor = colorRed;
    }
}