< Expanded Ketamine Spectrum >
1. Ketamine (Lowest Strength) - Very Light Purple - 
                            
                            #e5d0ff
                         - A soft, light purple that provides a gentle entry point for the lowest strength, promoting calmness.
2. Ketamine (Low Strength) - Light Purple - 
                            
                            #d1c4e9
                         - A slightly deeper purple that maintains a soothing quality while enhancing distinction.
3. Ketamine (Medium Strength) - Medium Purple - 
                            
                            #9575cd
                         - A vibrant medium purple that adds depth and is easily recognizable.
4. Ketamine (High Strength) - Dark Purple - 
                            
                            #512da8
                         - A rich, bold purple that signifies the highest strength, ensuring it stands out effectively.
5. PBS Control - Light Beige - 
                            
                            #e0d3af
                         - A warm, neutral beige that serves as a baseline control, providing balance to the palette.
6. Diazepam - Orange - 
                            
                            #ffa500
                         - A bright, energetic orange that creates a strong contrast and is easily identifiable.
7. Ethanol (Control for Diazepam) - Peach - 
                            
                            #ffcc99
                         - A soft peach that stands out against purples, maintaining a friendly tone.
8. BDNF - Green - 
                            
                            #008000
                         - A deep green representing growth and stability, offering a clear visual distinction.
9. Picrotoxin - Red - 
                            
                            #ff0000
                         - A vivid red that captures attention, indicating caution and providing strong contrast.

The “Expanded Ketamine Spectrum” palette utilizes various shades of purple for different ketamine strengths while ensuring that the colors are distinct enough to avoid confusion. The PBS control color is chosen to be warm and neutral, providing a good contrast against the purple shades. The other colors (Diazepam, Ethanol, BDNF, and Picrotoxin) are also selected to create a cohesive and visually appealing palette.

Suggestions for Improvement:

• Contrast Enhancement: To differentiate the ketamine colors from PBS, consider using a darker beige or adjusting the saturation of the purple colors slightly to ensure clarity in your graphs.
• Visualization Strategy: When displaying this palette in a bar graph, ensure that the PBS control is adjacent to the lightest ketamine shades to highlight the differences effectively.

Would you like further adjustments or to explore additional color options? Also, do you need help with any specific design aspects for your graph presentation?