When we use RGBA in Html we use sth like this.
<div style="Background: rgba (x, x, x, 0.dd)">Some Content</div>
How many decimals can you go in the dd(opacity). Is it browser dependent? Or are its limits specified in HTML standards?
The specification says it is a <number> which is defined as:
zero or more digits followed by a dot (.) followed by one or more digits
So there is no limit specified in the CSS spec.
I'd be surprised if any human eye could distinguish beyond two decimal places though.