About this detail of the Tiger
The Tiger called "TIKI" was whitewashed in early 1943, during the battle of Kharkov. The whitewash must have been applied by its unit "Das Reich", because the tank must have been delivered from the factory in a standard paint scheme. It's not clear when the whitewash was applied, but it was in place during the Third Battle of Kharkov.
In March or April, "Das Reich" repainted its Tigers in camouflage. It appears that more than one person did the painting, perhaps each crew painted their own tank, because the style varies. "TIKI" in particular was painted in an unusual style, as this photo shows. These paint schemes were retained through the summer.
There are no known colour photographs of "Das Reich" Tigers during this time. The colour of "TIKI" has therefore been a subject of speculation. We know that, when this Tiger was built, the three paint colours that became standard in 1943 (Dunkelgelb, red and green) were not yet in use. But they were available at the time of the repaint.
Artists have speculated that the whitewash was washed off "TIKI" in the Spring. They suppose that the original colour was Dunkelgrau, and that Dunkelgelb was applied in stripes over that. A number of publications have paintings of "TIKI" coloured this way.
I don't believe that this happened. "TIKI", like the other Tigers of "Das Reich", had a large black Balkankreuz before it was whitewashed. If the original finish had been exposed by removing the whitewash, this cross would remain. Even if the crew had overpainted this cross, the new paint would not have matched the old paint exactly. But this place on "TIKI" had a uniform dark colour.
It's also noteworthy that in some of the repainted Tigers it's obvious that three colours were used, one light and two dark. This all suggests that "Das Reich" were supplied with the three new colours of the 1943 scheme, and performed a complete repaint of their Tigers.
On "TIKI" itself, it seems that there were probably two dark colours. Some of the dark patches appear darker than others, and this difference is consistent across several photos (this example is contrast-enhanced).
Based on all of this evidence, I conclude that the most likely colours for "TIKI" in the summer of 1943 are the three standard colours of the period. The unusual painting style is due to the Dunkelgelb being sprayed on after the other two colours, which is not the usual sequence. This painting is based on those conclusions.
Also note that "TIKI" was not painted in Dunkelgrau originally, but had the first "tropical" scheme. This would still show through in a few places, such as the rear and the engine deck, when "TIKI" carried a thin whitewash finish.