EconomicGraphics is essentially framing a set of rules for all graphics artists involved in EyeCandiness to follow. By framing these rules we see to it that our graphics work well on a wide variety of displays, machines, colour combinations. EconomicGraphics is necessary because if our graphics are too rich there is a bigger chance of not seeing our graphics in all its glory on poorer target infrastructures. On the contrary heavy graphics might just appear very bad on such hardware. Typically the probability of finding poorer hardware, graphics capabilities is more in schools than anywhere else.
The following are the set of rules that I want to begin with. Please add your thoughts (add as comments):
Use only colours that can be seen on a 256 (or fewer) colour display, unless you really need the extra colours. It is very much possible to generate neat shadows under images even with a 256 colour palette. We should keep in mind that most of the machines that might run DebianEdu are very likely to be poor boxes in schools in villages. Colours that cannot be produced on lower colour depths spoil the image.
Never design sidebar graphics, etc., which cross one thirds of possible target resolutions (typically 640x480). Make sure that the image looks good when scaled down. This makes DebianEdu scale on a variety of hand-held devices too!
As it has always been, PNG becomes the unanimous choice for icons. It is generally preferable if icons do not have too much of transparent alpha. even up2date packages like gqview aren't good at handling alpha. a personal recommended value for thickness of alpha regions is not more than 2 pixels. This does not affect the image quality much when alpha is not supported. and 2 pixels wide alpha looks pleasing on those renderers that can handle alpha.
Every graphic artist knows that dithering is mandatory while indexing their graphics see to it that you DONOT dither transparencies
The obvious choice is the GIMP see to it that your images are available as Xcfs 'somewhere'