add swap operation, add ReOrder logic to extract.Colors

		}

	}

	if len(colors) == 2 {

		if Inverse(r) {

	if len(colors) == 2 && Inverse(r) {

		swap(&colors)

	}

	if order := Order(r); len(order) > 0 {

		ReOrder(order, &colors)

	}

	return

}

// swap modifies the color array passed as para.

// it will swap element 0 to 1 and 1 to 0

func swap(pColors *[]color.RGBA) {

	colors := *pColors

	tmp := colors[0]

	colors[0] = colors[1]

	colors[1] = tmp

}

// reOrder will change the order of the color array passed as param

// with respect to the 'order' array of integers.

// both array have to have the same length.

// will ignore any change if the indexes in the order array are out of range.

func ReOrder(order []int, pColors *[]color.RGBA) {

	colors := *pColors

	if len(order) == len(colors) {

		tmp := []color.RGBA{}

		reOrder := true

		for i, _ := range order {

			if order[i] >= 0 && order[i] < len(colors) {

				tmp = append(tmp, colors[order[i]])

			} else {

				reOrder = false

				break

			}

		}

		if reOrder {

			colors = tmp

		}

	}

	return

}

// GColors returns an array of colors based on a HTTP request.