I have puzzled over blue decomposing wood for years -- wondering if there was a natural cause or something like spraypaint by trail maintenance crews.
Blue stain fungi (http://www.fs.fed.us/r3/resources/health/field-guide/sds/bluestain.shtml) seems like a likely candidate. They are carried and facilitate bark beetle infestations and the Kenai Peninsula is plagued by spruce bark beetles.
Mold that engulfs and aborts the growth of boletes.
En Sierra del Águila, Ahualulco de Mercado, Jalisco.
Red dotty lichens?
on a dead tree trunk on the hills above the redwood grove (on the Pool Ridge trail)