I’d say the bottom one in particular is too dark. That accentuates the shadows of the 3D effect of the letters, creating that dark outline Omar is talking about.
The materials look really good, I think, but it’s hard to see. What is your lighting setup like?
For renders like that I’d take full advantage of something we can’t do in real life: Light and shadow linking. You can use accent lights to highlight areas of importance without affecting other areas, same for creating shadows.
If you like the darker tones, don’t worry. That will be achieved by the colors of the materials. Even a well lit dark color can give you that darker feel to it. If you look up “dark business cards” you’ll find tons of examples of what I mean.
