I don't know why the Replace dialog can't recognize the RGB font color of text that has the Hyperlink style (which, by the way, in my Word program from Microsoft 365 has the value RGB(0,80,253)). But if you use Format > Style > Hyperlink in the Find What box and the desired font color in the Replace With box, the Replace All button will replace the color of hyperlinks in the selected text; then you have to click No in the message that asks whether to search the rest of the document.
To do this with a macro, try this:
Sub ChangeHyperlinkColor()
Dim rg As Range
Set rg = Selection.Range
rg.Collapse wdCollapseStart
With rg.Find
.Format = True
.Style = "Hyperlink"
.Forward = True
.Wrap = wdFindStop
While .Execute And rg.InRange(Selection.Range)
rg.Font.TextColor = RGB(0, 176, 240)
rg.Collapse wdCollapseEnd
Wend
End With
End Sub