Here’s a vibrant yet balanced color palette designed around the specified color 
                            
                            #28899d
                        , suitable for a t-shirt design featuring the national flowers of Latin American countries. The palette includes two greens and is complemented by a dark background color that allows the flowers to stand out.

### Color Palette for T-Shirt Design

1. **Teal Blue**
   - **Color Name:** Teal Blue
   - **Hex Code:** 
                            
                            #28899d
                        
   - **Description:** This is the primary color of your t-shirt, a vibrant teal that symbolizes freshness and nature. It serves as a beautiful base, reminiscent of tropical waters.

2. **Forest Green**
   - **Color Name:** Forest Green
   - **Hex Code:** 
                            
                            #2c5f2d
                        
   - **Description:** A deep, rich green that adds depth and an earthy feel, reminiscent of lush forests. This color will provide a strong contrast against the flowers.

3. **Mint Green**
   - **Color Name:** Mint Green
   - **Hex Code:** 
                            
                            #a8e6cf
                        
   - **Description:** A softer, pastel green that brings a touch of vibrancy while maintaining a refreshing lightness. It complements the teal and adds a lively touch to the arrangement.

4. **Dark Charcoal**
   - **Color Name:** Dark Charcoal
   - **Hex Code:** 
                            
                            #333333
                        
   - **Description:** This dark background color provides a dramatic contrast, allowing the flowers to pop. It has a slight warmth and richness that enhances the overall vibrancy of the design.

5. **Coral Red**
   - **Color Name:** Coral Red
   - **Hex Code:** 
                            
                            #ff6f61
                        
   - **Description:** A warm coral that adds a lively splash of color to the palette. It evokes the vibrant florals typical of Latin American countries and contrasts beautifully with the greens.

6. **Sunshine Yellow**
   - **Color Name:** Sunshine Yellow
   - **Hex Code:** 
                            
                            #ffcc00
                        
   - **Description:** A bright, cheerful yellow that represents optimism and joy. It works well with the teal and dark charcoal, adding a bright focal point to the flower design.

7. **Soft Lavender**
   - **Color Name:** Soft Lavender
   - **Hex Code:** 
                            
                            #e1bee7
                        
   - **Description:** A gentle lavender that introduces a calming contrast to the more vibrant colors. It adds a floral touch and balances the overall palette.

8. **Warm Beige**
   - **Color Name:** Warm Beige
   - **Hex Code:** 
                            
                            #d9c4a4
                        
   - **Description:** Soft and neutral, warm beige acts as a grounding color in the palette. It enhances the vibrancy of the other colors without overwhelming them.

### Summary
This palette combines various shades to create a vibrant yet harmonious design for your t-shirt. The colors chosen will not only complement the teal base of the t-shirt but will also allow the national flowers to stand out beautifully against the dark charcoal background.