Edit the palette with poke

You can edit the palette directly by poking into RAM.

-ADDR-
0x3FC0 - Index 0 - Red component
0x3FC1 - Index 0 - Green component
0x3FC2 - Index 0 - Blue component

To learn more please see RAM: Palette.

Examples

Swapping two colors

You can swap two colors of the palette to use an alternative version of a sprite or tile and swap it back afterward.

initial_color=12 --initial color of your sprite you want to change
new_color=3 --color you want to use
poke4(0x3FF0*2+initial_color,new_color) -- swaps initial_color and new_color
sprite(...)
poke4(0x3FF0*2+new_color,initial_color) -- change it back

Red

function TIC()
  cls()
  -- make the first palette entry RED
  poke(0x3FC0, 255)
end

Green

function TIC()
  cls()
  -- make the first palette entry GREEN
  poke(0x3FC1,255)
end

Blue

function TIC()
  cls()
  -- make the first palette entry BLUE
  poke(0x3FC2,255)
end

Pal Function

Sets the palette index i to specified r,g,b, or return the colors if no r,g,b values are declared.

--sets the palette indice i to specified rgb
--or return the colors if no rgb values are declared.
function pal(i,r,g,b)
	--sanity checks
	if i<0 then i=0 end
	if i>15 then i=15 end
	--returning color r,g,b of the color
	if r==nil and g==nil and b==nil then
		return peek(0x3fc0+(i*3)),peek(0x3fc0+(i*3)+1),peek(0x3fc0+(i*3)+2)
	else
		if r==nil or r<0 then r=0 end
		if g==nil or g<0 then g=0 end
		if b==nil or b<0 then b=0 end
		if r>255 then r=255 end
		if g>255 then g=255 end
		if b>255 then b=255 end
		poke(0x3fc0+(i*3)+2,b)
		poke(0x3fc0+(i*3)+1,g)
		poke(0x3fc0+(i*3),r)
	end
end

Other languages in the snippets page.