When you represent transparency in a color representation in hexadecimal,

I'm implementing transparency options on the widget, but the hexadecimal color value is a problem. If you want to give 50% transparency to colors like "#33b5e5" in hexadecimal color expression, you can say "#8033b5e5" because 80 is 50%. And I said, http://www.dtp-aus.com/hexadeci.htmon this site

0% = #00
10% = #16
20% = #32
30% = #48
40% = #64
50% = #80
60% = #96
70% = #112
80% = #128
90% = #144

I also know how to express hexadecimal transparency. But it's a problem since the number goes over 100. When expressing colors, it's up to 8 digits. For example, if it's 80% transparent, it's #11233b5e5 but I can't because it's 9 digits.

How do we solve this?