SQL query to understand if customers are purchasing matching products

Question

I am trying to figure out the most efficient way to structure a query where the goal is to determine whether or not customers are purchasing "matching" products in an order. Here is an example of data structure.

order id	product id	product type	product colour
a	a1	shirt	blue
a	a2	shorts	blue
a	a3	shirt	red
b	a4	shirt	green
b	a5	shorts	yellow
c	a6	shirt	pink
c	a7	shirt	pink

So, in the example I would want to know if people who are purchasing both a shirt and shorts are matching the colour or those 2 products. Im sure this is a common cart analysis.

My initial plan is basically:

1. determine the orders that purchased both a shirt and shorts
2. create a temp table that stores the order id and the shirt colour
3. do the same for shorts join these two tables on order id and compare the two colour columns

so essentially I would have:

order id	shirt colour	shorts colour	match?
a	blue	blue	TRUE
b	green	yellow	FALSE

BUT, this doesnt seem like a very efficient way to do it and also doesnt account for situations where customers purchase multiple products like in the example order 'a'.

Any suggestions to improve this?