To apply a custom color palette in Excel, specifically for the THMX file type, follow these steps:

Step 1: Create a Custom Theme

1. Open Excel: Start the Excel application.
2. Go to the Page Layout Tab: Click on the “Page Layout” tab in the ribbon.
3. Select Colors: Click on “Colors” in the Themes group, then select “Customize Colors” at the bottom of the dropdown menu.

Step 2: Define Your Colors

1. Name Your Theme: In the “Create New Theme Colors” dialog, you can name your theme (e.g., “Excel Professional”).
2. Set Your Colors:
   • Click on the dropdown next to each element (e.g., “Accent 1,” “Accent 2,” etc.) and select “More Colors.”
   • In the Colors dialog, go to the “Custom” tab and enter the hex codes for the palette:
     • Primary Blue: #0070C9
     • Light Blue: #A3C5E0
     • Dark Gray: #4B4B4D
     • Light Gray: #D9D9D9
     • Green: #00B050
     • Orange: #F6A600
     • Red: #E03C31
3. Save Your Theme: Once you have entered all colors, click “Save” to apply and use your custom theme.

Step 3: Save as THMX File

1. Save the Workbook: Go to “File” > “Save As.”
2. Choose THMX Format: In the “Save as type” dropdown, select “Excel Theme (*.thmx)”.
3. Name and Save: Choose a name for your theme file and click “Save.”

Step 4: Apply Your Custom Theme

1. Open Excel: Open any workbook where you want to use your custom theme.
2. Go to Page Layout: Click on the “Page Layout” tab.
3. Select Your Theme: Click on “Themes” and find your custom theme in the list to apply it.

Tips:

• You can always modify the theme later by repeating the above steps.
• Make sure to use contrasting colors for better readability, especially for text and background.

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