I've been thinking about making a pixel art oriented graphics app for a while, and came to the conclusion that there are just two things you really need (and which no app currently provides both of) - a simple and efficient interface / set of tools, and good color selection features.
While making a full graphics app like I wanted, is probably too big an undertaking, I think a palette creation tool is actually quite realistic...
You can see that as colors get lighter/darker, they also change hue (lighter colors become more yellowish; darker colors become more blueish). You can also see that the individual color "ramps" share some shades (eg. in the second example, a reddish color is part of both the red and purple ramps).
I want to create a tool that lets you create these ramps, and to link them together into a usefully presented palette. Below are a couple of my ideas. With all of them, you will be able to select a range of cells, and have the hue/saturation/lightness/red/green/blue components automatically change smoothly between them (eg. increase hue by 4% and lightness by 10% for each successive cell), or to interpolate between two cells.
Hexagonal Grid:
It's still basically just a 16x16 grid (meaning up to 256 colors), but the hexagonal cells mean that each has 6 neighbours rather than the 4 of a square grid, so it's easier for a color to be shared between multiple ramps, and to have ramps radiate outwards from a single color (usualy either the lightest or darkest). It's very simple, but quite versatile.
Nodes:
Here, there is no grid at all - you can just create color nodes wherever you like, and connect them with lines to form ramps (or click on the lines to create a new color between two others). I think for small palettes it would be really useful, but it would be messy and awkward with larger palettes (imagine a 256 color palette!).
Wheel:
My final idea, is a sort of wheel. The example below shows it as a kind of 32x8 grid (256 colors), but I think 16x16 would be better. Looking at the original palette examples, you can see that the example below is the same as the second of those, but warped into a circle. Although the example below doesn't demonstrate it, you could have ramps radiating out from the centre, or running in a circular direction, or a mix of the two.
The other interesting thing is that I want to use the CIE-L*c*h* color space ( http://www.colourphil.co.uk/lab_lch_colour_space.shtml ), which is a variant of the Lab color space used by Photoshop etc. It has the advantage of being perceptually uniform - and means it will allow you to change hue, without affecting the perceived lightness, for example (normally, bluer colors appear darker than yellow colors) - and it means that we can interpolate between colors properly ( http://coderwall.com/p/_w1rra ).
This is what my color selector looks like at present:
Anyway, just thought I'd share what I've been up to.
If you think any of those palette systems sound better than the others, or if you can think of a good one yourself, please let me know
That is a cool thread on pixel joint.
That site always depresses me because I don't think I'll ever be to the level some of those artist are over there.
EDIT: If you're building a palette building application why not just give the user a choice of how they want it laid out. From what I understand from that thread it doesn't matter so much and is personal preference.