I have the same question as G3nome.
The fact that there is no longer a card limit for silvers does not present a need for their color to change to gold. They are epic cards, with (generally) less of an impact when played and are therefore silver. Changing their color is the opposite of equal treatment!
Some arguments to bring back silver linings:
- Legendary cards should be impressive; wow, a legendary is being played! Gold linings reserved for legendaries helps with this, a tiny gold triangle much less so.
- The collections look much cooler with gold-, silver- and bronze-lined cards to distinguish legendary, epic, rare and common. I would even propose a different color for rares and commons as well (rare = bronze, orange color, common = wood or something, dark brown color). This gives the cards more visual impact when played.
- Last but not least, having silver cards would create possibilities for additional depth, flexibility or restrictions, thereby allowing for better tweaking and balancing of cards and mechanics. For example, cards only interacting with or spawning cards of specific color(s). Clear linings to indicate color would be essential then.
I see many silver linings!