> Firefox choose to change the foreground color on tabs end to make names
> easier to read.  I guess it isn't supported by Emacs. So I use to set
> tab-bar-tab-name-function to tab-bar-tab-name-truncated and
> tab-bar-tab-name-ellipsis to t.  It helps distinguish the separation
> between tab names.  Is it expected for the truncation to not applying
> anymore with the code you sent?

Unfortunately, an ellipsis takes too much screen space.
When "…" is not displayable, then "..." will take 3 chars
from every tab name, and even "…" with variable-pitch fonts
takes almost the same space as "..." with monospaced fonts.

But using a faded foreground color like in Firefox is
the right thing to do.  After adding this to the end:

          (add-face-text-property (- (length (nth 2 item)) 3)
                                  (length (nth 2 item))
                                  'shadow nil (nth 2 item))

produces such nice look where tab names are fading to the right: