PDF link annotation color space (border)-CodePudding

I try to understand the color entry for a Link annotation.

Section 8.4.1 of the PDF 1.7 specification is about annotation dictionaries (common to all annotation types) where the table 8.15 describes an entry C as

An array of numbers in the range 0.0 to 1.0, representing a color used for the following purposes:

• The background of the annotation’s icon when closed
• The title bar of the annotation’s pop-up window
• The border of a link annotation

The number of array elements determines the color space in which the color is defined:

0 No color; transparent
1 DeviceGray
3 DeviceRGB
4 DeviceCMYK

So I assume that the link annotation in this form

<<
  /A <<
    /S /URI
    /Type /Action
    /URI (www.example.com)
  >>
  /C [
    0.22
    0
    0.55
    0
  ]
  /Rect [
    28.346
    801.543
    50.586
    813.543
  ]
  /Subtype /Link
  /Type /Annot
>>

should be a color in the color space DeviceCMYK (four numbers in the array) and should be some greenish color. But it appears that the color is treated as RGB

(screenshot from Foxit PDF reader, similar to Acrobat)

R: 56/255, G: 0/255, B: 140/255

So there is a misunderstanding on my side here, but where is it?

CodePudding user response：

Your understanding is correct, it seems this is a bug in many viewers.

XODO displays the border correctly.