Is possible. As a general rule, if nothing is specified, the metal zipper will have a slider of the same color as the element, and the other zipper will have a slider of the same color as the tape color.
(Slider with a retrofit puller is only available in metal color)
The color of the slider on the product page is a sample, so the color will change depending on the zipper you order.
If you want to change the color of the slider, please describe it in the order memo.