If the style attributes contain "background:$color" the column lose the sorting arrows (example A), but is still sortable
the syntax works correctly if "background-color" is used. (example B)
in wikitext the additional attributes of "background" are disabled (bg-image position/bg-size bg-repeat bg-origin bg-clip bg-attachment) so "background" is a short variant of "background-color"
btw the deprecated bgcolor attribute works as expected. (example C)
In cases of "sortable" extends "wikitable" the issue is the same.
Link to examples: Benutzer:Boshomi/T156585
{| class= "sortable"
|+ |
;example A: class= "sortable" style="background:#ABC" in Col A (fail, Col A <s>is not sortable<s> is sortable, but the arrows are hidden.)
|-
! style="background:#ABC;"| Col A
! Col B
|-
| A1
| B1
|-
| A2
| B2
|}
{| class= "sortable"
|+ |
;example B: class= "sortable" style="background-color:#ABC" in Col B (ok)
|-
! Col A
! style="background-color:#ABC;"|Col B
|-
| A1
| B1
|-
| A2
| B2
|}
{| class= "sortable"
|+ |
;example C: class= "sortable" bgcolor="#ABC" in Col B (ok, but deprecated )
|-
! Col A
! bgcolor="#ABC" |Col B
|-
| A1
| B1
|-
| A2
| B2
|}