Manager Derek McInnes has revealed Rangers and the SPFL forced Aberdeen to wear their grey away kit at Ibrox.
The Dons traditionally play in red when facing Rangers away and had planned on doing that for Sunday’s clash, which ended in a 2-0 defeat.
However, Rangers appealed to the SPFL to stop Aberdeen wearing red as it clashed with the orange kit worn by keeper Allan McGregor.
McInnes said: “We were told we had to wear grey.
“Rangers clearly don’t like us in red and they insisted their goalkeeper wear orange.
“That is the reason.
“I have never known it to be honest in all my years.
“But the SPFL backed Rangers and allowed them to wear the orange kit.”
Rangers confirmed a second placed finish in the Premiership ahead of Aberdeen with the victory at Ibrox.
The Dons were denied a fourth successive victory over Rangers in Glasgow this season as referee Don Robertson awarded two second half penalties which were both converted.
Rangers’ second penalty was particularly damaging as defender Andy Considine was also sent off after Robertson brandished a second yellow for the incident.
Considine put his arm up to gain leverage in a jump and it lightly brushed Nikola Katic. There was little contact but Katic threw himself to the ground.
That Dons keeper Joe Lewis was hit in the face by Jermain Defoe in the first half but no action was taken will have added further frustration for the Dons.
There is no mechanism to appeal a second yellow unless it’s an incident where a player was wrongly judged to have committed an act of simulation, or a case of mistaken identity.
Considine will be suspended for the clash against Celtic at Pittodrie on Saturday.
Celtic need just one point to secure the Premiership title.
McInnes said: “The second penalty absolutely killed us.
“It was embarrassing.
“I cannot understand how he came to the decision it is a sending off and a penalty. We have to deal without Andy for next week.”
The suspension to Considine is the latest blow to a Dons squad already depleted by injury.
Winger Connor McLennan was also taken off at Ibrox having sustained a hamstring tear. Aberdeen are minus wingers Gary Mackay Steven and Niall McGinn through injury.
Greg Stewart is struggling with sciatica and was introduced off the bench against Rangers.
Defenders Shaleum Logan and Tommie Hoban have also been sidelined through injury.
McInnes said: “We had only one natural wide player left with Connor McLennan.
“Then he went off injured.
“We were playing a centre-forward wide right already and a left-back wide so it did curtail what we wanted to do.”