This is more like the parents asked to borrow the car for a week, and a week later when you asked about it you find out they sold it.

One of Argentina's is dark blue with purple flames on the bottom. But even just roygb would probably get the point across.

But I assume the teams use different colors. So wear the reddest jersey the orange yellow green blue purple.

Oohhhh yes, even better make it jerseys for teams that are in the world cup. Less vibrant but more plausible deniability.