I'm sure it can be done, but you better hope you mix enough for the whole floor, and you don't need to do any repairs, unless you calibrate your measurements.

As for black slate and silver shadow, I have a feeling it would look like white grout against the black slate.

Thanks Bill for the feedback. I have a small carton of Raven and one of S. Shadow. I am going to mix and match some tiny batches using the small epoxy A&B I got at Lowes. I read on the JB forum that you can freeze this mixed epoxy grout and defrost and it is still usable. Have you heard of that? I have my tile samples set up to grout in the next few days.

Ummmm that's not quite accurate. You can put in the freezer (has a MUCH lower freezing temp). That doesn't mean to freeze it, per se. Secondly, that will only slow down the chemical reaction that hardens it. It will NOT stop it, so you can't put it in the freezer indefinitely.

Use a VERY accurate scale to measure proportions.

Like a scale used for weighing chemicals (0.01 grams) or reloading ammunition (0.1 grains).

You can get away with a larger (and less precise) scale to make large batches, since the errors are not as significant in the larger amount of material.

Make sure you write down what you decide on.

Many of the manufactures have gotten very good at holding color long term, and a small repair batch can then be mixed and adjusted for a perfect match.

Thanks to both of you. I now have 4 different powders of spectralock colors. At less than $4 a cartoon it is worth the investment to see what these are like. I have one small bucket of A&B epoxy. I will do my dry prep and then mix the A&B and take what I need of the epoxy to make up my small portions of samples. I will work fast. The colors I have are:
1) Platinum
2) Silver Shadow
3) Raven
4) Smoke Grey

Note, I don't know why I wasn't liking the Smoke Grey for my slate, but today I think is might work. Maybe I thought the under color would be too warm. But it actually may be the warm color I need. It looks good with my sample board of elements.

Questions for Bill, Brickeyee, & et al:
1) Do you think the Smoke Grey will look white with my black slate stone when done up?
2) Can I just pour the powder in the grout spaces to get an idea of the color or do I need to mix the epoxy in with the powder to get a good visual of the final color? (It sure would be easy to just fill the gaps with powder:)

1) It'll defnitely look light.

2) I wouldn't. But if you mix the epoxy, you NEED to mix the whole unit.

Well that Smoke Grey is too pink for me. The samples are done and are drying. They are rough estimates. I used a measuring tablespoon to measure the dry powders together and mixed well. The most promising one is the 2 parts Platinum mixed with the 1 part S. Shadow. I have the Raven mixed too. I like the color of Raven but it isn't mixing as well with the S.Shadow and looks a lot more speckley. But that might be more rustic looking. I don't think you will see the graininess without getting on the floor to look.

Didn't see your post Bill. I mixed the whole unit up and used bits of it in my ziplock bags that I had my combos placed and labeled. I tried to mix in the bags by mushing up the powder with the epoxy that I'd drizzle in. It sort of worked. I hope the stuff sets up. One is kind of runny. I will post pictures tomorrow evening at the latest.