Some children take red plugs out too because they like to put 'bows' on their kite tails and use red ones from the kite to make them:
Other children make use of the thick/thin attributes of the plugs and make patterns which include colour and thickness.
Patterns & Patterns
These examples are patterns because they are composed of a unit which repeats. We too often fall into the trap of using this as a 'definition' of pattern. A trap because such a definition doesn't include cases like:
in which no unit repeats.
Make kite tails with these rules - the number aspect is too obvious when written in this form. They are patterns but they do not contain a unit which repeats. A pattern is in fact a pattern because it allows prediction of what comes next (and next after next and next after next after next ...)
Allowing children to make the 'repeating unit' kite tails, which seem to come naturally, and then offering some of these others with the question "Is my kite tail a pattern?" encourages a broader understanding of the concept of pattern.