Pavlovia: Argument should be an array of numbers of length 3

URL of experiment:

Description of the problem:

I want Psychopy to drag a new Polygon colour every trial from my conditionsfile. It worked fine when I had set the Polygon colour to “constant” but since i changed it to “set every repeat” I always get the error “the argument should be an array of numbers of length 3”.
In my conditionfile I specified the colour as -0.7,-0.7,-0.7 (rgb colour space) so there should be 3 numbers.
I had brackets around the numbers at first but I saw in another post that I should remove them and place them in the Polygon Properties. Unfortunately that didn’t helped.

I am very grateful for any help

Hi There,

Try having a unique column for each value.
So the input in FillColor should read

$[Col1, Col2, Col3]

Where you have 3 columns in your conditions file (one per colour)

Here is a demo :slight_smile: Polygon_colour.psyexp (5.1 KB) conditions.xlsx (8.6 KB)

Hope this helps,


Hi Becca,

Thanks a lot for the reply. Sadly it didn’t worked for me. I still get the same error.

Hi There,

Did the demo attached above work if you push that to pavlovia and run try it in pilot mode?


Hey Becca

Your version did not worked either on my laptop. On a colleagues Laptop both of them worked so the error seems to be with my Laptop and not with Psychopy/ Pavlovia.

Thank you so much for your time and help.