Hi Ximena!
These factors are the conversion from IOPs to concentrations on the bases of empirical relationships. For OLCI you have:
chl = 21.0 ∗ (a_pig443)^1.04
tsm= 1.06 * (bp + bw)^0.942
The factors and exponents were derived with NOMAD data mainly (and some coastal data). If you have your own data measured in situ, you could try to derive this relationship by yourself and change the factors conveniently to your study area. That should improved the conversion to fit ranges closer to your expectations.