The technical answer here is NO. Glass will appear frosted; no color can be added. Metal will engrave black (if it's stainless steel) or silver (it engraves away the paint/powder coating to reveal the stainless steel underneath); no color can be added.
Wood will engrave some shade of brown, which can vary depending on the wood, settings used on the laser, and variations within the wood piece itself. Because the laser etches into the wood, color in the form of paint can be added after the engraving. Depending on the size and complexity of the graphic, color-filling can be labor and time intensive and can add to the cost. The results can add a stunning touch to any piece and are often easily worth the effort and extra cost.
Acrylic - and there are many different types - also often results in an etching into the material that can be color-filled.
So the long answer is that wood can be color-filled. It can also be painted first, and then engraved after. Wood does not equate to lack of color. And we are huge fans of the simple beauty of using a variety of stains in any given piece to add contrast and visual interest.
Acrylic by nature comes in a huge variety of colors, so you could combine these with color-filling and include about any color in the spectrum!