Two types of fires, fission and fusion.

The color of that molecule or element when some level of the particle undergoes fission or fusion to release the different colored fires we see. Fission and fusion of molecules and elements at different particle levels through fire would mean different and more bright colors are emitted in the matter screens than compared to the elements and molecules at Earth norm energy levels in the normal all matter calculator screens. Historically fire is both a heat source and a light source, the only addition of thinking here is that light always has color. The image of fire we see is the color of fission/fusion.

The fires of creation. The flames of creation.

Heating, light, and combustion. Use of all fuel types to speed up the research in all fuel types, first for heating dynamos, second for lighting screens, and third for creating different types of matter energy in engines. Using as many fuel types as we can and advancing them will help us discover which fuels can be used and then made into another fuel on the color tree, then back again, creating a fusion/fission cycle for the fuel. Research into all fuel types increases energy output of dynamos ,the vibrance of builder screens, and the power of engines. We would also discover igniter fuels that are hot enough to ignite another fission/fusion reaction, so the first fuel is ignited normally until it reaches a certain temperature and then another fuel that cannot be ignited normally is introduced and ignited as the second fuel starts to be the only fuel going in. Certain fuels burning or exploding differently might also cause different elements/molecules to undergo fission/fusion at different temperatures and states than the temperatures and states normally required. So as the second fuel is introduced, the heat is not enough to ignite it, but the first fuel which is burning is undergoing fission/fusion differently than other fuels which cause the second fuel to ignite.

Historical Classified idea: The old calculators could have had fire versions where all the elements and molecules would burn similar to fuel which would light up the screen similar to a modern screen, or more similar to a screen made of colored candles. This would have been before electricity was added to all matter calculator screens to light them up. This would have been the first fission/fusion screen. An element/molecule hammer, taking apart and building atoms/molecules. The Builders Calculator screen. This would have been the screen the Free Builders used. The mechanical device similar to the music box would have controlled the different flows fuel or elements/molecules into the fires in the pixels to change their colors and image. The fuel is what you take apart or can also build, and what comes out of the exhaust is what you build or take apart. So the idea of exhaust is also the creation of something new similar to fission/fusion if you keep the exhaust, then you are building something new or taking something apart to make it into parts, with so many pixels you would have created a lot of different molecules/elements which would come out of the exhausts.

Modern day idea: The Builders Engine, or an engine that uses different fuels in different pistons just as The Builders Screen uses different fuels in different pixels, turning the engine into fusion/fission engine where all of the exhaust is kept. With so many fuels we would just need to create a fertile soil out of the new elements/molecules the exhaust makes to make new but different fuels out of the now different elements/molecules. So with so many variations of fuel, your exhaust can always be used to make new but different types of fuel that is then used again in the engine. Recyclable fuel.

Future Idea: Having builder screens that cause fission/fusion reactions in elements or molecules to create different colors in each pixel on the screen, so the computer screen builds and takes apart particle as the image is emitted. Using infinite theory, you can theorize that in the future the screen would be able to do the same thing as a fission/fusion reactor, fission/fusion of the elements to create energy and produce elements in higher demand during the process.

They could have also put colored see-through objects in front of the light to change the color of the light and therefore the pixels, by having a mechanical machine cycle each pixel through the colors it has in a rotating disk the machine turns.