I use API and mine says yellow. When its sort of looks bluish but with a yellow tint I add one more drop cap it and give it a quick shake. If it doesnt stay yellow I add one more drop and do it again. It should stay yellow.
If I had to guess id say 9dkh.
Are you shaking or swirling it between drops? I add 5 or 6 quick drops then cap it and shake it. Then add drop by drop shaking inbetween each drop.