Is there a reason to use uppercase letters for hexadecimal CSS color values?
It really doesn't matter, but what is important is having a convention and sticking with it. I like to use strict sass-lint rules to enforce lowercase hex values, and short values where possible (e.g. #fff
instead of #ffffff
).
Here are my reasons for choosing lowercase;
Easier and faster to type (I have changed the key bindings of my caps key and using shift is just awkward, especially mixing numbers and letters)
It's easier to search for something if you know what to expect. (Say you're rewriting old code to Sass, you've fixed all occurrences of
#aa99cc
, but what aboutAA99cc
,Aa99CC
,A9C
,a9c
? Linting will pick out these problems for you)
I am not aware of any differences other than personal preference. Personally, I prefer lowercase since it's quicker to read, although in very short strings such as CSS color values, the benefit is probably negligible. Really, I think it's just because I think lowercase looks better.
Hexadecimal, however, is traditionally written in uppercase, so maybe I'm - strictly speaking - in the 'wrong'.