Here are three different options for muted color schemes featuring pink, green, and mustard tones, suitable for an Excel spreadsheet:

Option 1: Earthy Pastels

 <Earthy Pastels>
1. Muted Blush - 
          
          #E2B2B2
        - A soft blush pink that introduces warmth without overwhelming.
2. Soft Sage - 
          
          #B7C9A7
        - A muted sage green that adds a refreshing, natural vibe.
3. Dusty Mustard - 
          
          #D2C68A
        - A warm mustard that brings a subtle brightness to the palette.
4. Pale Peach - 
          
          #F3C6B3
        - A gentle peach that complements the pink and adds a soft touch.
5. Olive Green - 
          
          #A8A35B
        - A muted olive that grounds the palette and pairs well with other colors.
6. Creamy Beige - 
          
          #E8D8C3
        - A warm, creamy beige that serves as a versatile neutral background.
7. Light Teal - 
          
          #A4D9D6
        - A pale teal that adds a hint of freshness without being overpowering.
8. Soft Grey - 
          
          #D9D9D9
        - A light grey that provides a clean, sophisticated backdrop for the palette.

Option 2: Warm Naturals

 <Warm Naturals>
1. Rose Quartz - 
          
          #D48B8B
        - A muted pink that adds warmth and elegance to the design.
2. Dusty Olive - 
          
          #AFAF8C
        - A soft, muted olive that complements pink and mustard beautifully.
3. Muted Mustard - 
          
          #D6B34B
        - A warm, earthy mustard that introduces a cheerful element.
4. Blush Beige - 
          
          #F2D3D3
        - A light, soft beige that enhances the palette with warmth.
5. Sage Grey - 
          
          #B7B8A9
        - A muted sage-grey that brings a sophisticated touch.
6. Faded Coral - 
          
          #F6B8B8
        - A soft coral that introduces a hint of vibrancy without being distracting.
7. Pale Mint - 
          
          #B6E1E0
        - A light mint that adds a refreshing quality to the muted colors.
8. Creamy White - 
          
          #F7F4ED
        - An off-white that serves as a neutral backdrop, enhancing the overall aesthetic.

Option 3: Subtle Vibrance

 <Subtle Vibrance>
1. Dusty Rose - 
          
          #C48A9A
        - A muted pink that adds a gentle warmth and richness to the palette.
2. Soft Fern - 
          
          #A3BFA3
        - A muted, soft green that brings a calming, organic feel.
3. Muted Mustard - 
          
          #D6C76A
        - A subdued mustard that introduces a unique pop of color.
4. Peachy Beige - 
          
          #E4B9A1
        - A soft peach-beige that enhances the warmth of the palette.
5. Light Olive - 
          
          #B3B43B
        - A muted olive that adds depth and pairs nicely with the other colors.
6. Dusty Mint - 
          
          #A8D8D2
        - A pale, muted mint that introduces freshness while balancing warmth.
7. Warm Taupe - 
          
          #B59C8E
        - A comforting taupe that serves as a neutral base for the color scheme.
8. Light Grey - 
          
          #D9D9D9
        - A subtle grey that provides balance and sophistication to the design.

Each of these palettes incorporates muted tones and maintains a harmonious balance, making them ideal for an Excel spreadsheet.

Which option resonates with you the most? Would you like further refinements or additional options?