I forgot to mention I am using Better Status Colors plugin ( https://github.com/wiz78/BetterStatusColors ) , and i wish to continue using it...

You can override Status colors in your config_inc.php file (see $g_status_colors). If you create a new, custom status, then it needs to be defined in this configuration as well (see admin guide).

It's not fully clear to me what the plugin does, and how it interacts with MantisBT. If the custom colors (as mentioned above) work without the plugin, then please contact its author for support.

Thank you, @dregad, for your quick reply.

I have read admin guide for this specific topic, but I have not found any entry about how to override TEXT color linked to status.
As far as I've understood from the guide, I can override status color, but linked labels (i.e. status names) are always black coloured.
Am i correct? If so, could you please help me understanding how to change status name colour (if feasible)?

Sorry I misunderstood. It is not possible to selectively change the text's color.

The only way to do this that I can think of, would be to create a plugin relying on jQuery to achieve what you want (similar to how Better Status Colors plugin works).