Hi Mik, the difference between V4 and V5 comes from the new theme functionality in V5.

The problem was that having a white color with transparent gap had poor visibility in the dark theme in areas where the line is going over top of a white shaded object.

To get better visibility these lines are now drawn with alternating colors instead of one color with transparent gaps and the line pattern is "dashed" with equal draw size and gap size instead of the previous "long dashed" that has a shorter gap size. This happens now in v5 when the viewport has a dark background color.

The blue happens because the 2nd color is automatically generated by inversion.

Your color having
red1 = 255
green1 = 255
blue1 = 0

gets a second color of

red2 = 255 - red1
green2 = 255 - green1
blue2 = 255 - blue1

which gives 0, 0, 255 (color blue)


I should be able to adjust this to use the v4 behavior (use transparent gap instead of 2 color line and don't switch to even dashed line style) when you have customized StraightSnapLineColor= in moi.ini .

And maybe I should set up a way to directly specify the 2nd color in a theme instead of only using inversion.

If you have the default StraightSnapLineColor= in moi.ini (StraightSnapLineColor=103,0,0,0) then the color will come from the theme's defines.inc file under STRAIGHT_SNAP_LINE_ARGB_COLOR .

- Michael