Update docblock for get_header_textcolor() and header_textcolor()

[theMikeD]

These two functions return the colour in HEX but that is not indicated in the docblock. Since we are pulling the docs from code, this should be added.

[DrewAPicture]

@azaozz Can you please review the changes in 36336.2.diff​?

[azaozz]

Sure, docs look good :)

[DrewAPicture]

In 37083:

Docs: Improve the DocBlocks for get_header_textcolor() and header_textcolor() to mention that they both retrieve color values in the HEX format.

Props theMikeD.
Fixes #36336.

[swissspidy]

I don't really like HEX format (why uppercase anyway?). 6-digit hexadecimal form sounds much better. See twentyfifteen_hex2rgb() for an example.

[DrewAPicture]

Replying to swissspidy:

I don't really like HEX format (why uppercase anyway?). 6-digit hexadecimal form sounds much better. See twentyfifteen_hex2rgb() for an example.

I can get on board with "hexadecimal form" or similar. Do hex colors always save as 6 digits? I seem to recall a case where a default could be supplied as 3-digits and return as such, might've been fixed.

[theMikeD]

Are letters considered digits in hex format?

3 vs 6: I thinks it good to specify that it returns 6 since 3 is valid in other contexts.

[SergeyBiryukov]

In 39888:

Docs: After [37083], change "HEX format" to "3- or 6-digit hexadecimal form" for clarity.

Props swissspidy, theMikeD.
Fixes #36336.