Light emitted from a low density plasma, kinda like the opposite of trying to see through fog over a great distance (since the plasma is emitting, rather than scattering and blocking the light)
Is wavelength related to how much we can see into the sun?
Yes, because the photon mean free path (how far photons travel before being scattered or absorbed) is wavelength dependent, and it is the product of the mean free path and density that determine how 'deep' we can see optically.