An easy way to match color? (Gimp)

I'm trying my hand at crochet-look swimwear. I've been working all afternoon on the top and have come out with something I really like. I took a break, made supper, etc... But now that I'm turning to the bottom, I sadly note that I have misplaced the paper on which I jotted down the color values (hue/saturation/lightness) which I used on the various layers to achieve my colors for the top. And I'm not having much luck "eye-balling" it.

So, aside from starting all over, does anyone know an elegant way to transfer a "colorize" value from one Gimp file to another? Or is there a way to display the exact values of a given base color pre-dodge/burn? I don't see a way of making the eyedropper work, for I am not painting, I am "colorizing" the entire layer, preserving in that way the knit texture. Painting would blot over the texture.

Help appreciated. Thank you.

Assuming you saved your work in XCF or PSD format couldn't you activate the layer(s) that contain the color values from your work to this point? I'm not exactly sure how you are colorizing your work but I've matched colors by using the layer that contains the colors I want and used the eye dropper when I zoomed in quit close (like 400 to 800%). It matched well for my purposes.

But, you may be doing something a little different.

I think you're right, I am doing something a little different..... and probably backwards from how it should be done! *laughs* What you're suggesting would help me put that particular color on a brush, but that isn't how I made the color in the first place (which may be where I have gone wrong).

I'm making a crochet-look bikini. So to achieve that, I have a greyscale crochet pattern which I used as a fill. The next step was to use the "Colorize" dialogue on that same layer. The dialogue has three values: hue, saturation, lightness. By manipulating those, I came up with a nice yellow. The next step was to add highlight/shape through burn/dodge on the same layer. Anyway, I repeated these steps for the trim layers as well.

Now that I've moved down to the briefs, I discover that I have misplaced the paper on which I jotted down all those hue/saturation/lightness values. So when I try to colorize, I just can't seem to find the same combination of hue, saturation, and lightness I had before.

I have a feeling my procedure is not the best practice. Thank you though for the suggestion. If I weren't doing things all backwards, it would probably work great!

Your second sentence here pretty well explains your first. Sorry, but there's no good way to discover what values you might have used, unless you happen to know the exact grayscale values you started with, and what algorithms were applied to achieve the end result. If you do have that information, then it would be a matter of simple mathematics to figure it out, but if you don't, you're out of luck.

Next time, work as non-destructively as you can. If you were using Photoshop, I'd suggest you use an adjustment layer, which would allow you to have your colorization as a separate element from your grayscale source. The whole purpose of adjustment layers is to prevent exactly the situation your in now. One thing you can do with them is drag or copy them from image to image, in order to apply the same colorizations (and other effects) to all. Unfortunately, one of GIMP's often complained about long-time weaknesses has been the lack of this feature. Unless it's been added in recent versions, GIMP does not support adjustment layers.

You can sort of fake the effect, though, with translucency. It's not a perfect solution by any stretch, but it can work fairly well in many situations. Instead of applying colorization to your source layer, apply color to a second semi-transparent layer, placed above the source. For something as simple as colorizing grayscale fabric, it should work just fine.

There is a script that can match the colours from one image to another. It's not very accurate, but might help.

http://www.ve3syb.ca/software/gimp/myscripts.html

Here is a guide that can help find out where to save it.
http://docs.gimp.org/en/install-script-fu.html

Many thanks, Chosen, for the advice on how to proceed in the future. Lately I have been making my textures from scratch, so I slipped into a bad habit in the use of the greyscale "fabric" texture. I know that, surely, it must also be a bad idea to do my wrinkles/highlights and so forth on the same layer, so I will try, finally, to learn the right way of doing them to save myself time in the future. *smiles* Thank you again.

And thank you also, SnakeArsenic, for the linked script. I will look into that and give it a shot. The link might prove useful for a lot of other things, I think, so I am very grateful.

I terribly sorry I just tested that script and it doesn't work on the latest GIMP, it said 2.4 so I assumed it would work on 2.4.7 so I've updated it myself and the link to the updated script is below:
http://www.snakehole.net/gimp/scripts/match-colours.scm