so you you all know we have a warm light in minecraft with the sun and torches and all that. but I feel like we need some more colder lights added to minecraft. like, instead of having it go really dark at night have a bit of blue light or/and maybe have a block or torch which radiates cold light?
just an idea to have some more natural light.
You can turn the brightness up if it is too dark at night, and sunlight (sky light) is tinted blue at night, although this does aggravate the issue of the game not having actual darkness (even on Moody the lowest light level is 5% of maximum brightness, which is something that should be fixed, as shown here).
Otherwise, adding a new type of light would require adding an entire new layer of data to the game, which currently handles sky light and block light as two entirely different things (block light is tinted yellow and flickers while sky light is white or tinted blue and visually changes brightness/color depending on the time of day. Block light also melts blocks like ice and snow while sky light does not, even in hot biomes, making it a "cold" light, if you were thinking of this. Making a block that emits sky light instead of block light could be done but the brightness would vary with the time of day).
Is it possible to code in a light block that doesn't melt ice?
Yes, it's possible (Mojang is already doing it with sea pickles, mushrooms, bedrock-version enchanting tables, and the non-standard forms of block light). It won't be quite what you want, however, because you have to set it to a very low number and therefore place them more frequently. Keeping them at the same placement range and brightness means you currently can only use skylight, and it sounds like it's an on-off switch with accompanying lookup to get time-of-day/brightness value (rather than setting to a numeric value of your choice like with block light).
I'm probably misunderstanding what Caver is saying, but it sounds like he's saying that block light and sky light are on two separate layers. It makes sense and probably makes blending easier for the light engine, so making a light that emits continuous light like blocklight but doesn't have certain effects (flicker, heat) is probably as simple as creating a few new properties and adding in a third layer for something (ie, heat values). That would retain just the two forms of lighting, but still give us 5 distinct types of lighting (skylight, heatless noflicker blocklight, heating noflicker blocklight, heatless flicker blocklight, and heating flicker blocklight) with a potential option for a sixth type (skylight with heat, such as on the inside of glass in an enclosed room). Interestingly enough, this would also allow for a rework of how fire light works in that we could tie the brightness of fire to the burn time of whatever's on fire, allowing the flames to dim over time. That'd be a rather cool effect.
and it sounds like it's an on-off switch with accompanying lookup to get time-of-day/brightness value (rather than setting to a numeric value of your choice like with block light).
There is nothing that prevents a sky light source from having a light level other than 15; it works exactly the same as block light with the exception that all blocks with a direct view of the sky are assumed to have a light level of 15, so it propagates downwards until the first block that blocks light (this means that a sky light source would have to have a nonzero light opacity or it will allow light from the sky to propagate downwards through it without falling off with distance; the game could easily be coded so that "sky light" emitting blocks would be treated as blocking light even with an opacity of 0; for example, in TMCW I use a light opacity of 127 to mean that a block is fully opaque (values of 15 or higher are effectively the same as all light is blocked, vanilla uses a default value of 255, which I changed to 127 as I use a byte instead of int to reduce memory), while slabs and stairs have an opacity of 126 to indicate that they aren't fully opaque).
The main issue is that the game uses a table to convert sky light levels to a visual and effective (e.g. used by mob spawning) brightness based on the time of day (the actual level remains the same; F3 will show the sky light under an open sky as always being 15 regardless of the time of day).