No, I'd say the colors definitely vary. I ordered some rectangular cushions in the lightest yellow and (8x6 the largest) and they were perfect. Nicely warm, faced up very light..wouldn't say white but white enough to wear with diamond eternity band (g diamonds)
These supposedly show more color because of the cut too.
Ordered a round (8.5mm I think) lightest yellow a couple months later....totally yellow. side, top, all angles.

I was SOOOOO hoping for the same color I got on the cushions.
Oh well, I am truly thankful for these cushions being the perfect color....I adore this ring and it is the most realistic sim ring I have to date.

Also, ordered a chinese white awhile back and could see no color at all in it. Compared it in all ways (upside down, etc,etc) to a clear one I have...no difference. I know others could see more difference in theirs so I'm sure there is a variation in these types of colors.