config_auto_item.less values are replaced

Hello
I've created a new template, based on default one. 
In my this new template, config_auto_item.less default values are replaced by others. 

For example, I paste congig_auto_item.less from default template into the same file in my template. 
After saving (save and close), some values are replaced by others  
@FCI_tab_bg_color_start: #3093c7;
@FCI_tab_bg_color_end: #1c5a85;
@FCI_tab_title_color: #ffffff;
are replaced with :
@FCI_tab_bg_color_start: #ffffff;
@FCI_tab_bg_color_end: #ffffff;
@FCI_tab_title_color: #ffffff;
 
And tabs are not visible.
I can't find what is going on.

If you can help...
Thanks.

hello
that already exist in item.less => less file is for generating color on item option admin
don't touch on config_auto_item.less
use item.less

Hello

I think you misunderstood me.

I don't want't to change anything. It's just that this file is changing itself. To test it, I pasted the whole content from default template, and after saving it, some values did change.
How is it possible ? I can't figure which parameter or other file is doing this.

Item.less seems not been changing color values in config_auto_item.less as it using it.

This file Can change because it used to generate css file via template option

Ok, thank you Micker.
I didn't realized that once (I don't know when), I had to change parameters templates. So it's ok now.

thanks for return