Conditional formatting with percentiles

[sairyg]

Hi,
I need to conditionally format a row of values based on percentiles - but i need four groupings and need four distinct colours (not scale colours).
The groupings are:
Blue - top 15% of values - i.e. 85th percentile and up
Green - the next 50% of values - i.e. 36th - 85th percentile
Amber - the next 25% of values - i.e. 11th - 35th percentile
Red - the bottom 10% of values - i.e. 10th percentile and below

(fyi i didn't choose these groupings!)

I tried using the colour scales method but can't have 4 scales and plus they don't want the shading - just those 4 colours.
I've ended up using the top and bottom ranked function and making four rules with this - which are (in order):
Bottom 10%
Bottom 35%
Top 15%
Top 65%

It seems to work but one value is left white and i can't work out why (have attached it). I've tried changing the 35% and 65% to see if it was just on the cusp but even going up and down by 3% doesn't do it.

Any help on this or a new way of doing it?