NX The original colors of the sketch curves are not displayed while entering sketch environment.

The original colors of the sketch curves are not displayed while entering sketch environment, all the sketch curves are displayed in brown color.

How to display the original colors of the sketch curves.

By default, NX overlays the colors of the movable sketch curves with the defined movable curves color.

if your sketch is fully defined/is not movable, the original color will be displayed. If you still want to display the movable sketch curves with the original curve's color, then you need to toggle off  "Show Movable". (But this will not evaluate the sketch and the sketch status will not be shown)