Is it just the letter that determines the colour, e.g. any cell ending "AB"
should be orange?

If so use these conditions

1 =RIGHT(A1,2)="AB"
orange

2 =RIGHT(A1)="B"
yellow

3 =RIGHT(A1)="A"
red

"P Beardshall" wrote:

Is it possible to conditional format for specific terms within a cell.

e.g. the addition a letter or letters to a number will change the colour of
the cell.

1A = Red
10B = Yellow
100AB = orange.