This video shows applying red for silver. I stopped the video after about 4 minutes because I am using an old brush and I needed to hold the vase closer to me which would have been out of camera range.  Also, it is horsefly season here in Japan and you can hear 1 or 2 buzzing around.
For more on traditional, lacquer based kintsugi see kintugi.com or https://www.kintugi.com/?page_id=80