Thank you for the answer ptoing. Very nicely detailed.
I have to say that hose restrictions are really bizzare to say the least. 3x1(4x1 on this picture) pixels?! It seems that it would take more planning than the C64 restrictions:D
Just looked at this again and saw your question which no one answered.
The restrictions are not too complicated, but a bit tricky to get used to.
You got a fixed palette, 16 colours to choose from (you can't use all at the same time).
Find the palette here (click on VIC at the top) http://www.colodore.com/
There are no real built in gfx modes for the vic20 apart from the char modes, but Aleksi Eeben has come up with an implementation which is very nice, and is the one Lackey used.
You get 22x11 4x16 pixel blocks (88x176 pixels). Each block can have up to 4 colours, 3 of these colours are fixed across the whole picture. The pixel ratio is closer to 3x1 than 4x1, but really somewhere inbetween.
One colour is the background colour, it can be any of the 16 colours.
One is the border colour, this can be any of the first 8 colours (as the name suggestes it also dictates the colour of the border around the image)
Then there is the auxiliary colour, which also can be any of the 16 colours.
And last but not least there is the char colour, which is unique per 4x16 pixel block, and can only be any of the first 8 colours.
The colours are in the right order on the colodore site, but just to be clear, first 8 are black, white, and then then dark versions of RCMGBY (in that order).
Hope this helps. Would love to see you (or anyone, really) do something in this mode.
Well, the VIC 20 has a very low resolution, so the hires pixels are almost as wide as the wide pixels on C64, the wide pixels are even wider. 4x makes sense that way, but on a real monitor they are closer to 3x1, but not cleanly or anything.
As far as needing more planning goes, I don't think so. What is important is to choose 3 good fixed colours, and then you can add the extra colours from 0-7 where needed.
Here is a really nice picture by Mermaid that shows really clever usage of the limitations.
demozoo.org/graphics/173648/
The fixed colours are black for the border (which is also used in the image, and light red and brown for background and aux (dunno which is which, does not matter either way). The light red and brown can not be used as free colours, because they are indexes 8 and A, so they are good choices for fixed colours, since they cover a good brightness range, as well as working as skintones.