Image trace won't recolor

@Tiina32958883uxp9 by any chance is the colours RGB or Grayscale. If Grayscale, in the Swatches panel, in the hamburger menu, click on the drop down, and change to RGB. Make sure there are nothing selected. With the Direct Selection Tool (White arrow tool), click on the stroke of the path (artwork) that you want to change colors; Once you have it selected, click on a color in the swatches panel. When done. Click of the image, and use the 'Direct Selction Tool and click on again. (White arrow tool)

I have attached a video that I recorded by doing what I did above (see tracing.mp4)—sorry, no sound, kids are asleep (it's 124am PST) — or with sound, https://youtu.be/-Cy5TfYuGK8