case insensitive - Is there a reason to use uppercase letters for hexadecimal CSS color values? -

i see colors in css properties values commonly written in uppercase form:

.foo .bar {   background-color: #a41b35;   color: #fff; } 

but can use:

/* same same */ .foo .bar {   background-color: #a41b35;   color: #fff; } 

it looks using lowercase values same, and, css values colors are not case-sensitive. lots of graphic design software use uppercase form. , common find uppercase notations in source code, looks there tradition.

i understand consistency thing, should same everywhere in software, standard doesn't give indication, people what want or what told do.

is there rational reasons this, historic, compatibility, old ie6 hacks, performances or practical reasons?

i not aware of differences other personal preference. personally, prefer lowercase since it's quicker read, although in short strings such css color values, benefit negligible. really, think it's because think lowercase looks better.

hexadecimal, however, is traditionally written in uppercase, maybe i'm - strictly speaking - in 'wrong'.