Personally, I think there is a combination of techniques in the Life-Saver image, some of them 2D. There may be more than one 3D render, with different materials, composited, or brush-blended into one another after rendering.
But just to look at a couple of possibilities:
The yellow and red hero life-saver looks to me to be a color-mapping of surface normals:
The leftmost Combine XYZ is an arbitrary vector.. you can think of it as the direction from which a magic light is shining. Where the surface normals are parallel to it, the dot product will be 1, and where they are opposite, -1. If we map that [-1 to 1] range to [0 to 1], that will fit in a color ramp, and we can decide what colors the surface will be, with respect to that direction. (The height-map is the one used to emboss 'LIFE SAVER' on the surface.)
The rather metallic looking life-saver linked to it could be just that. Here, I've surrounded it with colored emissive planes to reflect. For convenience, you can give your reflected objects this kind of material:
.. which means they will reflect in the surface, but be invisible to the camera, so you can put them where you like.
If you use EEVEE to do this kind of thing, then you have the Shader to RGB node, which lets you convert the light-response of a surface to colors, for further manipulation, further down you node trees. For reflections, you will have to set up Light Probe > Reflection Cubemaps.
Keeping the sampling low, without denoising, gives you some of that speckled texture.. but if you want 'official' stippling, then you could check out the answers here, which go some way towards it.