Yes, those were cool in the 1970s. HMIs have moved on. Why use them when high definition vector fonts are available and so much more readable. There's a lot of effort going into High Performance HMIs these days.
Unless you're building a HMI for a certain DeLorean upgrade?
You wouldn't happen to know the reason for this behaviour in the Designer?
I notice the same thing for other components (icons, progress bar, etc).
Same thing in the style popout menu.
If we were to supply the actual #161616 value in the property tree as part of the component schema, then the component will no longer honor the theming files and/or stylesheet.css as you are directly specifying a value which would override anything else.
Since the rules for applying colors/styling are based on a combination of inheritance and specificity, the props.bar.color value would be more specific than any other setting.