You can change the boundary color but it can't be removed.
In anycase, it doesn't matter the color of the border. Even if the border could be removed (it could be possible via custom coding), depending on your features when you zoom out to a certain extent all features in Analyzer View will appear to 'melt' together taking away the ability to discern borders.
I think a better idea to is to add a display scale to the features so that they disappear from view when the scale is at or beyond that level of discernability.
This can be done in Vector Data settings prior to Vector Set publishing.
Here is example of polygon features with white border that you can see no longer discern geometry at a higher scale to illustrate my point
Thanks for your message.
If I'm not wrong, there could be the chance to remove the border via custom coding.
Could you please provide me with an example of custom coding to
1) remove the color border
as well as to
2) change the colour of the border?
We would like to test both options
Thanks a lot for your support