It looks like the topic is becoming relevant.
In fact, there are very few proposals specifically for paint to restore the color of the fabric top. And all for some reason from England.
Here is the manufacturer's website:
Soft Top Reviver | Renovo International
Perhaps this is just a marketing ploy, but Renovo warns - before using paint, remove the impregnation of fabrics from other manufacturers)))
And here's an alternative:
Protex World | Soft Top & Leather Interior Restoration Products
It is not so categorical here, but they also recommend using only their line: cleaner - paint - impregnation :
Specially formulated to colour restore your faded canvas soft top this colour restorer will present a strong and even finish penetrating deep into your canvas top. Used after Protex Canvas Cleaner, colour restoring your top is the second stage in the Protex soft top restoration process.
protexworld.co.uk