Strictly speaking, you are correct. The key assumption for my statement above is that both objects are black-body radiators.

In practical terms, it still ain’t happening when the light source is a bunch of fireflies.

Aside: Lasers are a really weird case. The population inversion required for stimulated emission is basically the opposite of a classic thermal equilibrium. By some definitions, they are so hot their “temperature” wraps around to negative (i.e., less than zero Kelvin). That factoid took me a while to wrap my head around.