A very annoying bug.

Create a new color, associate default to it, save.  Only to find that this didn't actually save - the color is set to 0 bonus unless you go back into the design and update to default.  Particularly annoying for maps that have multiple scenarios.

Are you working with a scenario? Are "Colors" unlocked? You could also try Locking and then Unlocking a number of Categories that somehow must be at a higher level.?? - It's been a LONG time - but I seem to remember having some success with that.

Is it "Set-Up" based? If so, check the rules tab and select "Initial Setup."  The color-oriented rules could be part of the problem.  Don't ask me how they work, I always have to guess and check when working with them.

There's no doubt it's a bug. Most designers don't add colors later to existing maps, so they don't run into it. I happened to run into a color in an open game that I really liked, so I wanted to add that to my maps for both The Shire and LOTGR, both of which have several scenarios.

So they ARE scenarios.. I have changed colors on existing maps - though I can't remember if they were scenarios or not.  AND I have changed things like borders, factories, and dice mods to existing scenarios, and yes, there is a bug.  But there is a trick that often works when things don't 'take'.

As I described above. Sometimes you have to Unlock more that just "Colors." I think the bug is hierarchical and is tied to more than just "Colors."  For instance, just to see if it works, try Locking everything in the scenario.  Then unlock and see if it takes.

I just tried what Thingol suggested.  I don't think it's scenario related, because I did it in a board without scenarios. 

If I had to guess, there is a disconnect between the UI which by default displays 'default' and the backend database which by default is storing a zero.  Until you change the value, then change it back there is a disconnect.

Sounds like Thingol already has a workaround.

IMO, it's a minor annoyance, but yeah, would be nice if it was fixed.  Unfortunately, until WarGear makes Tom rich enough to quit his real job or he wants to share access to the site, these sort of minor annoyances are probably here to stay.