Sorry guys,
I was kept away from the forum!
It seems that the problem was resolved a month ago:
Lua runtime "Slot and entertainment - color / alpha out of range fix". (SkeletonJson.lua)
I had not seen this version of the lua runtime (found in Github/spine-runtimes/Commits), who is different than the the one you can download on the website !
I tested and everything is ok.(i'm still using the Coronas graphic 1.0)
Sorry for my english, i'm french.
Thank's again