Q:

Filtering for byte array in Wireshark

The Wireshark documentation for filters says (emphasis mine):

The "contains" operator allows a filter to search for a sequence of characters, expressed as a string (quoted or unquoted), or bytes, expressed as a byte array, or for a single character, expressed as a C-style character constant. 

Unfortunately, it only gives an example for strings but not byte arrays.
How do I express a byte array in Wireshark? 
I wonder whether it's more convenient than putting escaped characters in a string like "\xD0\x00\x0E".

A:

It turned out that the syntax of Ethernet addresses is actually not MAC address specific, but that's a syntax for byte arrays. So you can do
udp contains 48:65:6C:6c:6f

(an equivalent for udp contains "Hello").
The linked website says in a different paragraph:

Ethernet addresses and byte arrays are represented by hex digits. The hex digits may be separated by colons, periods, or hyphens

So the following (even mixed style) will be recognized as well:
udp contains 48.65.6C.6c.6f
udp contains 48-65-6C-6c-6f
udp contains 48:65-6C.6c-6f

