Yes, right now we don’t have style properties that target the date/time text of the xtrace display. You can only style the vertical line and the box. I recall a feature request being opened for this, but if not, I will open one.
This isn’t available through component properties at the moment, but this can be done through theming. Below is a CSS snippet you’ll need to add to a style overrides file. Note that !important is needed to override the style applied at the library level until these are exposed via component props:
fill: blue !important;
Theme files are in the gateway’s install directory: %installDirectory%\data\modules\com.inductiveautomation.perspective\themes\... . Check out the readme.md file in that directory. The last two sections in the file talk about making modifications to themes or building custom ones.
As an aside… We did open a ticket recently to add the ability to style the x-trace text via component properties.