In CSS3, you can create a white color using the RGBA color model by setting the red, green, and blue values to 255 (the maximum for each), and adjusting the alpha value for transparency. To create solid white, set the alpha to 1. Here’s an example:
background-color: rgba(255, 255, 255, 1); /* Solid white */
To adjust transparency, decrease the alpha value. For example, to make the white color semi-transparent, you can use:
background-color: rgba(255, 255, 255, 0.5); /* 50% transparent white */
This allows for transparent or semi-transparent white backgrounds.