I a planning on constructing a LED safelight for my darkroom. I want to use Lamina Light Engines LEDs. These are a ceramic substrate with many LED dice attatched. There is a red (618 nm) and an amber (589 nm) available. Both can be run at up to 18 watts and cost around $20. I do plan to include a current regulator with a brightness knob. Do you think the amber one would be safe? It should be really close to the Thomas sodium safelight. The LEDs do need a heatsink and current regulation to operate.