The greenish tint is caused by the TK40 (mixed with another lightsource in the foreground). I've tried ACDSee Pro6 with similar processing settings I use on my photos from the Ostwig mine and I could remove most of the tint. The other light was most likely your flashgun or someone trying to help you with a different lamp.
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We use LED-lights only at Ostwig.
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The now standard equipment consists of approximately 15 lamps between 100 and 2400 lumen and either a Panasonic FT3 or FS16.
It's amazing how much light is absorbed by slate. Wet slate is the worst. About 75 - 90 % of your light just disappears.
All lights are mounted on small tripods. We try to keep them out of view. The lights are a good mixture of flood and throw, several Spark SD6 for a good floodlight and other lights for background and highlighting details. Providing some good hidingplaces we don't even need the high or turbo setting on the lamps most of the time. There's no additional lightpainting.
We use 15 second exposure, f3.3 and ISO 100 for most photos.
Timewise you're looking at 5-10 minutes for setting up the lights, 5-10 minutes for testshots and rearranging the lights if required and about another 5 minutes for the actual photo. Certainly not the quickest way, but we tend to get some reasonable results. On advantage is that you've got something like a preview even without your camera.
You need to be careful with your scale. Keeping still for many photos can be very tiring.
Make sure you remember where you put all your lights as they're hard to find once they run out of power.
Some of the lights including the TK40 and some SPARK have a very distinctive green tint which needs to be removed with Photoshop, ACDSee or other suitable software.
Various tints of the LED mean you need to choose your lights carefully. You also need to stop overhelpful helpers trying to give you just that little bit extra light.
I've been asked to write this up properly and I always wanted to do so since last summer but work and some other gadgets to play with kept me away from it so far.
I use lightpainting with a Pentax W90 or WG-2 at work
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or on holiday as it is a lot quicker than the above method and requires slightly less equipment. Standard lighting is with a Wolf Eyes Super Storm 2 or Wolf Eyes T3 after some first attempts with a TK40. The TK 40 has too much spot. The exposuretime is ISO 80 and 4 seconds as the Pentax won't do more and panfocus rather than autfocus as on the Panasonics. Changing position from one side of the camera to the other while painting does help to get better results sometimes. Max ISO for larger workings is 400 anything higher has too much noise.
Flashguns with slaveunits (Firefly 3) are good for moving targets and fine details.
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With a good team you are a lot quicker than any of the above even in a large working. But you'll probably need 5 or 7 flashguns to light a large area and different to the first method you'll only see your result on the display of the camera.