What are differences between RGB vs RGBA other than 'opacity'
I have moved beyond using standard colors in CSS by declaring them orange , blue , aquamarine , etc..., and have been using rgb() like so for the same colors respectively, rgb(255,165,0) , rgb(0,0,255) and rgb(127,255,212) (thanks to the ColorHighlighter package in ST3). Upon altering a gradient for bootstrap .btn I came across rgba() . Quick research explains that a stands for alpha , and theres a whole bunch of integral math attributed to Catmull and Smith . It is also somewhat easy to find that the alpha channel is used for "alpha compositing", which can mostly be associated as "opacity".