Colors only shown... sometimes?

[baltasarq]

Yep, I figured that myself creating a program that writes using print64() with many colors. I've changed my strategy since then (I'm going to use icons). The strange thing is that this program is a port of a program compiled with z88dk using a similar library, in which attributes were not a problem. Now that I know the limitations of print64(), I wonder how do they do it.