The following should find red text in the document body and put it in a text form field. The colour will be the underlying style colour.
Code:
Dim oRng As Range
Dim strText As String
Dim oFld As FormField
Set oRng = ActiveDocument.Range
With oRng.Find
.ClearFormatting
.Font.Color = wdColorRed
.Replacement.ClearFormatting
Do While .Execute(Forward:=True) = True
strText = oRng.Text
oRng.Text = vbNullString
Set oFld = ActiveDocument.FormFields.Add(oRng, wdFieldFormTextInput)
oFld.Result = strText
Loop
End With
ActiveDocument.Protect _
Type:=wdAllowOnlyFormFields, _
NoReset:=True, _
Password:=""