Autofilter by conditional format colour

[timetabler]

Using Excel 2016

When auto-filtering by cell colour, where the cell colour has been defined by a conditional format. The autofilter includes some cells that don't meet the colour requirement, and in some cases ignores the cells that do meet the requirement.

The condition colours the cells based on the lower/upper standard deviation, as below. What happens on the data set is that when filtering Data1 coloumn for green cells (300 rows), some green cells are filtered, but other non-green cells are shown, and some green cells are not included in the filter.

Data1	Data2	Data3	Avg	Std	Upper	Lower
100 (green)	75	50 (red)	83	20.4	95.4	54.8
40 (red)	50	60 (green)	50	8.16	58.1	41.8
50	50	50	500		50	50

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When the conditional format looks is Cell Value > (upper) or < Lower.

I have seen lots of people having problems getting filter by colour to show, but this is just giving 'wrong' filters, in Excel 2016.

Any help or pointers, greatly appreciated.

 

[timetabler]

Digging deeper ...

When I filter by colour, the results are (for example) 89 and 99 and these are green. However, it also filters (non-coloured) 89 and 99 - these are within the std variation and so should not be coloured. (and excluded from the filter).
Example on Google Drive: https://drive.google.com/file/d/1VW0e1jXo2eoqJLRP_1sVyQIvcMZmCRAB/view?usp=sharing