How to identify this issue
- The stroke has the right width and the right position, and only the colour is wrong.
- The wrong colour is black, or a duller version of a saturated colour.
- The swatch was set from a picker other than RGB, a Lab or spot colour book among them, or the document colour mode is not RGB.
Solution
1
Reset the swatch from the RGB picker.
Open Layer > Layer Style > Stroke, click the colour swatch, and switch
the picker to RGB before choosing the colour again. Photoshop keeps the mode
you used last, so this is worth checking on every effect in the file rather
than only the one you noticed.
2
Convert the document to RGB.
Other colour modes are converted on upload, and converting in Photoshop
while you still hold the ink values leaves the decision with you.
Preparing a PSD carries the rest of the file
requirements.
3
Upload the file again.
Effect colours are read at upload and stored with the template, so a
template registered a while ago carries the record made then, and a
correction reaches your renders only through a new upload. The new template
carries its own UUID.
4
Render at the template's own width and compare.
Export the same file from Photoshop at the same width and set the two side
by side, rather than judging the render against the Layers panel.