Charcoal gray ( #333333 ) is quite dark and should provide a good contrast with the vibrant emerald green. However, if you’re looking for an even darker option, you might consider using a color like Jet Black ( #000000 ), which would provide an even stronger contrast and a more dramatic effect.

As for the all-caps logotype, using all uppercase letters can definitely convey strength and stability, which is great for branding. Here are a few tips to help you achieve an abstract logo style similar to Oakley or Nike:

1. Simplicity is Key: Both Oakley and Nike utilize simple shapes and lines in their logos. Focus on creating a minimalistic design that encapsulates your brand’s essence without unnecessary details.

2. Symbolism: Think about what your brand represents and try to encapsulate that into a single abstract shape. It could be something related to your industry or a conceptual representation of your brand values.

3. Iterate and Experiment: Don’t be afraid to sketch multiple ideas. Sometimes the best designs come from iterating on initial concepts. Try different shapes, angles, and forms until something resonates.

4. Negative Space: Utilize negative space effectively. This can create a unique and clever design that stands out, similar to how the Nike swoosh uses negative space to imply motion and speed.

5. Feedback Loop: Share your designs with friends or potential customers to gather feedback. Sometimes, an outside perspective can help highlight strengths or weaknesses in your design.

6. Inspiration: Look at other brands that have successful abstract logos and analyze what makes them effective. You can derive inspiration without copying them directly.

If you’d like, I can help you brainstorm more specific ideas or concepts for your logo!