Yes, we lose there is energy losses from Stokes shift. For example, when we shift from a high energy blue photon to a lower energy red photon we lose the difference in photon energy as heat. Blue LEDs are approx 55% efficient and red LEDs 35% efficient. Even with Stokes shift losses our fixtures end up being more efficient.
If, however, blue LEDs and red LED emitted at similar efficiencies our technology wouldn't work. We'd lose too much energy in the conversion. Luckily (for us) blue LED efficiency is projected to increase more quickly over the next few years than other colors (more R&D dollars behind them).
If, however, blue LEDs and red LED emitted at similar efficiencies our technology wouldn't work. We'd lose too much energy in the conversion. Luckily (for us) blue LED efficiency is projected to increase more quickly over the next few years than other colors (more R&D dollars behind them).