The W channel in quaternion and axis-angle F-Curves is now themeable (defaulting to yellow), instead of incorrectly blending the X and Y axis theme colors. The original blending math did not take into account that the hue channel actually wraps around, and so the blended color became blue instead of the intended yellow. Instead of fixing the math, the theme has been expanded for this W axis. The default color is set to the mathematically correct yellow. Co-authored-by: Sybren A. Stüvel <sybren@blender.org> Pull Request: https://projects.blender.org/blender/blender/pulls/143211