I had figured, but not that the color change was part of an intentional effort to make them like his own! It’s nice to feel what I saw in this was intentional, though. This is an expression of his care for her, but bound up in that is also his desire for her to come back, despite what she said. He couldn’t do anything to change her leaving, so instead he does something to exert control over her personal possessions, most likely letting himself imagine she’ll come back. It’s a small scale situation compared to what we know he does in the movies which take place around this show, but it shows the same tendency he displays in them: this is a guy who not only gets mad, sad, and scared about losing people, but who reacts to it by trying to control what happens around him before controlling himself.
And Ahsoka knows this about him, though not the wrong it has already led him to commit with the Tuskegee children, and the wrong it will lead him to commit with the Jedi children (and all the others who will suffer.) For this situation, it doesn’t bother her, it moves her, and they are partied in happier terms than the last time. She likes being thought of, and a little taking up of personal space, in this case by touching her old weapons, can be welcome as a sign of love and trust between people who know and care for each other as much as they do. But her understanding of him is part of why she’s been so guarded. She knows what he wants and that she can’t give it to him, and it would hurt them both more if she had to tell him, again, that she wasn’t coming back. (As it is I think that despite her efforts, that’s what would’ve happened after Mandalore if the events of the story had had room for it.) It demonstrates how Ahsoka can be drawn to someone with that force of personality and will, while also knowing how to set and maintain the boundaries she needs.