According to https://www.w3.org/TR/2008/REC-SVGTiny12-20081222/text.html svg should support all colors for text, but on my gear S3 only some colors like white, black, red, green, blue, magenta and cyan work. Even using a color filter after rendering the text fails. It feels like some color-limiting filter is applied to the text after rendering by the system.

How can I overcome this issue?

It renders correctly on the emulator, but not on the actual device, which is really frustrating.
The Gear S3 runs Tizen 3.0.0.2 the emulator is wearable-3.0-circle-x86

Example:

<svg>
<text text-anchor="middle" x="180" y="280" fill="#C0C0C0" font-size="300px"> 12</text>
</svg>

renders a white 12 on my watch but a grey one on the emulator.

UPDATE:

I narrowed it down, it is linked to  ambient mode.  When I use  ambient_support=”disable” it works as intended. This is confusing, because the watch supports  high color mode i.e. tizen.systeminfo.getCapability(‘[…]/screen.always_on.high_color’); (I cannot post the full path due to some forum restrictions) yields true