Why is there only one crystal color and no other colors?

Only one color is currently available. Due to the RGB light effect, only the crystal color shell can completely pass through, and the shells of other colors can only pass through part of the light, resulting in a poor light effect.

Can its RGB lighting effects be controlled only by buttons? Is it possible to set it up directly through the Steam Deck?

For RGB lighting control, you'll use physical buttons as the current method. Direct configuration through the Steam Deck isn't possible currently. However, this design ensures you can control the lighting, whether or not the Steam Deck is in use.

Will its RGB lighting effect consume the battery of the Steam deck and affect the usage time?

The RGB lighting has a built-in 150mAh lithium battery, please rest assured that it will not consume the power of the Steam deck itself when in use.