Human eyes give more importance/ have higher spectral sensitivity to light in the yellow- green spectrum under bright/ daytime conditions.
This is the reason why light sources that also emit light in the green wavelengths (including white lights) are perceived as brighter. Just a human bias. In fact it's a good illustration why we are interested in PAR ( equal importance to light between 400-700nm) instead of lux/lumens ( importance given according to human perception of brightness).
In summary, one can't say 2 light sources with different spectrum have the same or less PAR just on how bright they look.