Just to expand on what Nick said or to say it a different way. Probably no need to but I feel its always good to hear things in a different way
In blitz, atleas there is no such paletts for images you load. Although some bmps and other file formats do contain paletts, blitz does not give you access to that info.
However, you can create a palette for the purpose of speed in blitz, and oh how you need to every trick you can in blitz!
A palette is simply an array of colors(integers) information. Each color is then reprisented by the array index.
Traditionally an array of 256 colors is used. This is because gray scale images range from 0 to 255. In addition the array reprisenting the screen is usually a byte array, although this isnt possible in blitz.
To keep things simple, especially if you intend on using grayscale images to draw onto you screen array, then I would suggest you stick to a 256 palette. But if you really wanted to you could create a larger palette, and use the RGB of the picture to reprisent the index. So Red could mean index 0->255, Green 256->511, Blue 512->1023 wich would give you a palette of 1024 colors.
There is also another benefit of using a palette. This is indeed highlighted in a fire routine and thats the added bonus of blending. By that I mean you can add two indexes, such as 200 + 150 then divide it by 2 and you get 175 which if the palette is set up right should nicely blend in the middle.
