Wie ändert man die Bindungsfarbe bei Verwendung eines hooks ?

In Teil II Operation of ChemFig Abschnitt 9 Connecting Distant Atoms ist die Syntax des ?-Hooks beschrieben:

Fortunately the character ? has an optional argument:

?[<name>,<bond>,<tikz>]

where each field takes its default value if it is empty:

• The <name> is the name of the hook: all alphanumeric characters (a…z, A…Z, 0…9) are allowed. The name is a by default. In the first occurrence of the hook with this name, only this field is used.
• <bond> specifies how the atom with the current occurrence of the named hook is to be bonded to the atom with the first occurrence of the hook. There are two ways this can be done. First, this field can be an integer representing the desired bond type: 1=single bond, 2=double bond, etc. (See the table on page 5 for the bond codes.) Second, the field can be one of the bond character codes, provided that this character is between braces.
• <tikz> will be passed directly to TikZ as we have seen with regular bonds.

Also einfach der <tikz>-Option die gewünschte Farbe überreichen:

\chemfig{
  ?
   -[:195,,,,red]
   -[:50,,,,red]
   -[:80,,,,red]
   -[:20,,,,red]
   -[:-130,,,,red]
  ?[,,blue,ultra thick](
    -[:10,,,,red]
    -[:-10,,,,red]
    -[:40,,,,red]
    -[:-170,,,,red]
    -[:-195,1.2,,,red]
  )
}