Was the KJV "too highly colored in many places with the party ideas and opinions of those who made it"? In the Emphatic Diaglott, the second paragraph under the heading &quot;To the Reader&quot; states:

But can it be fairly said that such is the case with our present English Version? We opine not. Though freely acknowledging that it is sufficiently plain to teach men the social and religious duties of life, and the path to Immortality, yet it is a notable fact that King James' Translation is far from being a faithful reflection of the mind of the Spirit, as contained in the Original Greek in which the books of the New Testament were written. There are some thousands of words which are either mistranslated, or too obscurely rendered; besides others which are now obsolete, through improvement in the language. Besides this, it has been too highly colored in many places with the party ideas and opinions of those who made it, to be worthy of full and implicit confidence being placed in it as a genuine record. In the words of Dr. Macknight, &quot;it was made a little too complaisant to the King, in favoring his notions of predestination, election, witchcraft, familiar spirits, and kingly rights, and these it is probable were also the translators' opinions. That their translation is partial, speaking the language of, and giving authority to one sect.&quot; And according to Dr. Gell, it was wrested and partial, &quot;and only adapted to one sect;&quot; but he imputes this, not to the translators, but to those who employed them, for even some of the translators complained that they could not follow their own judgment in the matter, but were restrained by &quot;reasons of state.&quot; [bold mine]

Is there any historical record as to the veracity of this statement about the wording of the King James Version?
It has been calculated by some that 83% of the New Testament part of the  Authorised Version (see Wikipedia - William Tyndale footnotes 9 &amp; 10) is fully attributable to William Tyndale. If that be true (and from my own studies I do not doubt it) then any comment about the AV being biased in any way has to distinguish between any supposed bias in Tyndale separately from any supposed bias in the AV translators.
Scrivener's learned Greek Text of 1894 has shown what texts (Erasmus, Beza, Stephanus and Computensian Polyglot) were used in which places by the AV translators and so that, also, would need to be examined with regard to any supposed 'bias' regarding the choice of source.
It is noticeable that the AV translators favoured Beza, in one important place,  by adding his words εκ σου 'of thee' to the words of Luke in 1:35 turning 'which shall be begotten, shall be called Son of God' into 'which shall be begotten of thee, shall be called Son of God' : a very noticeable difference with serious implications.
And it is certainly true that one can discern places in the AV where the translators favour certain doctrinal views which are later expressed in detail in both the Westminster Confession and the Savoy Declaration.
One example of this is where the AV translators mis-translate Romans 5:18 δι ενος δικαιωματος as 'by the righteousness of one' (mis-representing a prepositional genitive as a possessive and adding an article not present in the original). Were they correct, then the concomitant expression δι ενος ανθρωπου in Romans 5:12 should be translated 'by the man of one' which is clearly ridiculous.
(See the Englishman's Greek New Testament Literal Interlinear Translation and Green's Literal Translation which have the correct reading.)
'By one man' and 'by one righteousness' is the correct translation. But the mis-translation which would have a schoolboy rightly castigated in Greek class is clearly an interpretation which favours the doctrine of Dr John Owen who influenced the Savoy Declaration of 1658 which contains support for the concept of 'active and passive obedience'.
However the quotation cited by the OP above, and the entire text in the link provided, bears not one single reference to the  AV and therefore (either from just that quotation, or from the entire article) no evidence whatsoever is offered of any bias at all, only a statement of unsubstantiated opinion.
The writer goes on to mention Vatican manuscript 1209 which is the Codex Vaticanus so it becomes obvious that the argument is not really against the AV, or rather Tyndale, or even the matter of English translation at all, the argument is against the Greek Received Text, as such.
Thus the above comments are singularly insufficient to persuade myself to leave the most commonly available English translation of the Textus Receptus, the Greek 'Received Text', in favour of what is being argued for, namely the Greek Text of 1881 and thereafter, which leans heavily on the Codex Sinaiticus and the Codex Vaticanus, which disagree between themselves in 3,000 places in just the four gospel accounts of Matthew, Mark, Luke and John, as publicised by Dean John Burgon in his book 'Revision Revised' 1881.