index.js
function setRGB(color, r, g, b, a) {
    color[0] = r;
    color[1] = g;
    color[2] = b;
    color[3] = (a !== undefined) ? a : 1;

    return color;
}
function setRGB(color, r, g, b, a) {
    color[0] = r;
    color[1] = g;
    color[2] = b;
    color[3] = (a !== undefined) ? a : 1;

    return color;
}
function setRGB ( color , r , g , b , a ) { color [ 0 ] = r ; color [ 1 ] = g ; color [ 2 ] = b ; color [ 3 ] = ( a !== undefined ) ? a : 1 ; return color ; }
Updates a color based on r, g, b, a component values
@param  {Array} color   - RGBA color array [r,g,b,a] to update
@param  {Number} r      - red component (0..1)
@param  {Number} g      - green component (0..1)
@param  {Number} b      - blue component (0..1)
@param  {Number} [a=1]  - alpha component (0..1)
@return {Array} - updated RGBA color array [r,g,b,a] (0..1)
Updates a color based on r g b a component values