The Stay In Line Lip Liner in Luminous color by Jason Wu Beauty was reviewed by Kathryn in a video. She mentioned that the lip liner is creamy and easy to apply. The shade, Luminous, is described as a cocoa nude but appears more like a medium warm terracotta brown. Kathryn liked the color and mentioned that it can make any lip color look good. She applied gloss in the center to enhance the look. Overall, the lip liner received positive feedback for its creamy texture and versatile shade. However, no potential drawbacks were mentioned in the review.