As talked about in the last post we have 22 essential colours (including transparency). These are loaded into memory at the start and do not change.
We then have 10 more colours loaded into memory that we can change when loading the next level.
The Amiga uses 12 bit colour, and you state each colour using a 3 digit Hex value. The arcade also used 12 bit colour so we have access to the same colours that it used. The arcade however displayed upto 384 colours on screen, we have only 32 colours to work with.
What usually happens when reducing the amount of colours is you lose all the depth out of your graphics. With the dark colours often being overlooked in favour of a variety of palette. What follows is usually a bit of a garish mess with no shading and a flat feel.
I have paid particular attention to retaining the depth of the original graphics, so although the colours may be different the level of grading is the same. Take the car for example.
The arcade version on the left uses 7 reds in total, with it being the only place on the level reds are used that much it would be a waste to dedicate that many colour slots just to the car. That said, the car is very iconic so it has a priority. In this case I have dedicated 2 colours to it, 623 and 823.
The darker shades come from skin tones and Jimmy’s reds in the essential list. So by grading between the pink tones of Jimmy and the brown tones of the skin we are able to create very smooth grading over 6 colours for the car. Hence we retain almost all the depth of the original graphics (we lose 1 grade). Colours 623 and 823 are not needed for level 2 so they are swapped out.
Check out the sprites comparison below, the arcade versions are on the left again. I gave priority to skin tones, as these are the colours you see the most throughout the game. By reducing the saturation of certain browns we can then reuse those colours for background colours. The output is almost identical.
Another example of colour choice, Billy uses 3 blues in the arcade version. My version uses 2 and then a dark grey for the other. The mid blue is then desaturated a bit so the it is less jarring when combined with the dark grey. Your eye doesn’t notice the difference unless it’s side by side with the original :)
By desaturating certain colours we then achieve a palette where combinations are more achievable, and by keeping the very light shades vibrant we retain the vibrancy. Overall the palette may be a bit more grey we still get that pop from the sprites, and we have gone from 384 colours to 32.
Regarding the resolution, we have chosen 256x240 to remain faithful to the arcade. Resolution has an impact on the feel, and seeing as we would gain a performance increase, this feels the right decision.