Conditional formatting

[Bob L]

I have a file that the first column are categories of food. Is it possible to have a formula in conditional formatting that alternates the color for every categories?

So cake and donut would be gray and pie and the next one after donut would remain white. The number of row per categories isn't fix as you can see.

Thanks in advance.

Cake
Cake
Cake
Cake
Cake
Pie
Pie
Pie
Donut
Donut
Donut
Donut
Donut
Donut
Donut

 

[Fluff]

How about

+Fluff New.xlsm
	A
1	Food
2	Cake
3	Cake
4	Cake
5	Cake
6	Cake
7	Pie
8	Pie
9	Pie
10	Donut
11	Donut
12	Donut
13	Donut
14	Donut
15	Donut
16	Donut
17
18
Main

Cells with Conditional Formatting
Cell	Condition		Cell Format	Stop If True
A2:A16	Expression	=MOD(SUMPRODUCT(--($A$2:$A2<>$A$1:$A1)),2)	text	NO

 

[etaf]

Ignore,
Did not see the previous reply

i can only see doing this with a helper column

Book1
	A	B	C	D	E	F	G	H
1
2	Cake			0
3	Cake			0
4	Cake			0
5	Cake			0
6	Cake			0
7	Pie			1
8	Pie			1
9	Pie			1
10	Donut			0
11	Donut			0
12	Donut			0
13	Donut			0
14	Donut			0
15	Donut			0
16	Donut			0
17				1
18
19
20
Sheet1

Cell Formulas
Range	Formula
D2:D17	D2	=MOD(IF(ROW()=2,0,IF(A2=A1,D1, D1+1)), 2)

Cells with Conditional Formatting
Cell	Condition		Cell Format	Stop If True
A:J	Expression	=$D1=1	text	NO

 

[Peter_SSs]

Another helper-column option (helper column can be hidden) that keeps the formulas very simple is

Conditional Format in Groups.xlsm
	I	J
1	Food	0
2	Cake	1
3	Cake	1
4	Cake	1
5	Cake	1
6	Cake	1
7	Pie	0
8	Pie	0
9	Pie	0
10	Donut	1
11	Donut	1
12	Donut	1
13	Donut	1
14	Donut	1
15	Donut	1
16	Donut	1
Cond Format In Groups

Cell Formulas
Range	Formula
J2:J16	J2	=IF(I2=I1,J1,1-J1)

Cells with Conditional Formatting
Cell	Condition		Cell Format	Stop If True
I2:I16	Expression	=$J2	text	YES

 

[Bob L]

How about

+Fluff New.xlsm
	A
1	Food
2	Cake
3	Cake
4	Cake
5	Cake
6	Cake
7	Pie
8	Pie
9	Pie
10	Donut
11	Donut
12	Donut
13	Donut
14	Donut
15	Donut
16	Donut
17
18
Main

Cells with Conditional Formatting
Cell	Condition		Cell Format	Stop If True
A2:A16	Expression	=MOD(SUMPRODUCT(--($A$2:$A2<>$A$1:$A1)),2)	text	NO

This is perfect. Thank you!!

 

[Fluff]

Glad we could help & thanks for the feedback.