Deceptive Colors - Importance of Value and How to Reveal it.

I have been working on the final version of the striped shawl I posted a few weeks back. I have done some adjusting of the design, but mostly I have been focused on choosing what colors I want to use.
Back when I was quilting I learned about a tool called a 'ruby beholder' that is basically a transparent piece of red plastic you can look through. The idea is to gather the fabrics you wish to use in your quilt and examine them through the red viewer. The red cancels out the differences in hue allowing you to see the different fabrics in terms of contrasting intensity, or value.
I have a selection of skeins of the planned yarn (Wool of the Andes Tweed) and yesterday I spent time grouping them in sets of 4 to 6 skeins, taking photos then saving another copy of the photo in gray scale. The gray scale photo makes clear whether or not the contrast of value between the colors is enough to be effective. It is remarkably difficult to tell the true contrast in value between yarns from a colored photo.
For example:

appeared to be a grouping of blues and greens with fairly good contrast and I quite liked it as a possibility until I took a good look at the gray scale version:

As you can see, the first and third skeins (from the left) in the center row have almost identical intensities, as do the top and bottom skeins, and the second and fourth skeins. It looks more like a collection of three colors of two skeins each than my planned six-skein grouping. This might very well still work as long as I am careful to not place the colors of same intensity next to each other in the final pattern. For that the gray scale photo will be invaluable. Huh, it seems by chance I separated the similarly-valued yarns from each other without realizing it. Perhaps I have an internal 'ruby beholder' after working with quilts for so many years?

You might ask what is the importance of contrast, if your eye can perceive the colors as different, won't it be contrast enough, regardless of what the gray scale tells us? That might be fine if you enjoy looking at the colors set out on a display tray in your home, where you can enjoy them from close up, but for garments (and quilts) the visual impact is most often seen from a bit of a distance and if you use colors similar in intensity next to each other it will not have nearly the same impact as using colors that have a distinct and differing value from each other.

Out of the eight color sets, I think I have found two or possibly three that will work. Next step, determining the rate and placement of increases to create the shape that will match my sketch of what I want the shawl to be. 

Color Choice via Image Swirl

There are many conversations among crafters about choosing colors for a project. Many of us consider ourselves color challenged, and ask for reassurance or advice from others on choosing yarns or fabric. I tend not to, or at least I haven't for a long time, but there are enough areas in my life where I second guess myself that I can relate :-} Even if you are 'color confident', this exercise may be of use when you are looking for fresh combinations for future projects.
Lots of people will tell you to find a painting or piece of fabric or pottery or photo in an interior design magazine you like, and choose from among the colors used. When using such things, I find it easier to focus on the colors if I choose an abstract design, rather than a representational one.
Google has come up with a neat little search tool called Google Swirl.
I used it today to find colors to go with blue.
This first image is the screen shot of what I brought up with the search terms 'blue abstract'.

This second image is what came up from selecting the center image in the 3rd column above.

The image below came up from selecting the third large thumbnail from the top, counting clockwise from the screenshot above. I may not use all these colors in a project, but I certainly have some new ideas! I would likely have come up with the turquoise and pinks on my own, but the golden yellow is something I might not have thought to add, and the darker greenish tones would definitely not have been among my first selections.

So, if you could use a little more confidence when selecting colors, go forth and Google!