Solar panels come in a variety of sizes because of manufacturer differences, but not a variety of colors. Generally, you will see solar panels that appear either blue or black, on top of either a white or black backing, and either a silver or black frame.
Blue panels are "polycrystalline", meaning the silicon cells were formed by combining multiple silicon crystals. They have an appearance almost like stained glass windows up close - lots of small fragments reflecting the sunlight in slightly different angles.
Black panels are "monocrystalline", meaning the silicon cells were cut from a single pure block of silicon. These are generally very sleek in appearance, especially if the backing paper is also black. These tend to be higher in efficiency than polycrystalline panels, but also slightly more expensive because of the manufacturing process. These are now the industry standard for most homes because of their aesthetics. Most residential solar panels these days are "black-on-black" or "triple black" (black monocrystalline silicon cells on black backing paper with a black frame). However, either type of panel will provide ample power for a home solar solution.
There are some companies that provide a "panel paintjob" to match your shingles or roof material, but the drawback is a significant drop in efficiency. Any coating on the surface of a panel will prevent light from reaching the photovoltaic elements, and thus partially defeat the purpose of installing them in the first place. ESP does not provide any such product and does not support modification of panels or arrays post-installation.
There are also products called "solar shingles" that either cover or replace the shingles of your existing roof. ESP does not provide these products because they are generally more expensive and less efficient than standard solar panels, and while there is a lot of hype around them, we have yet to see real-world evidence that they provide a good value proposition for homeowners.