Solution:

1) Select the 'Format' menu and select 'Slide Color Scheme...'. (The Color Scheme dialog box appears.)
2) Click the 'Standard' tab.
3) Select the desired color scheme to change, from the 'Color Schemes' group. (The selected color scheme is highlighted.)
Color Scheme
NOTE: Use the scroll bar to access more color scheme choices if necessary.
4) Click the 'Custom' tab.
NOTE: Each color in the 'Scheme Colors' group is indicated with a line and a tag, for example, Background, Shadows, Fills, Title Text, etc.
Scheme Colors
5) Select the desired scheme color to change, from the 'Scheme Colors' group. (The selected scheme color is highlighted.)
6) Click 'Change Color...'. (The appropriate dialog box appears.)
7) Do one of the following:

a) To select a standard color:

1] Click the 'Standard' tab.
2] Select the desired color. (The selected color is highlighted and displayed in the New Color box in the lower right hand corner.)
Standard Color
3] (Optional) Click 'Preview' to preview color selections without making any permanent changes.
NOTE: After the color changes have been previewed, 'Preview' becomes dimmed until another color is selected.
4] Click 'OK'. (The Color Scheme dialog box reappears with the new scheme color highlighted in the Scheme Colors group.)

b) To customize a color:

1] Click the 'Custom' tab.
Custom Color
2] Press and hold down the left mouse button over the arrow.
3] Drag the arrow up or down the vertical color bar to change the luminance.
NOTE: The numbers located in the 'Lum', 'Red', 'Green' and 'Blue' list boxes change as this is done. The numbers can also be typed in the related boxes.
4] Press and hold down the left mouse button over the cross-hair.
5] Drag the cross-hair over the desired color.
NOTE: The numbers in the 'Hue', 'Sat', 'Red', 'Green' and 'Blue' boxes change as this is done. The numbers can also be typed in the related boxes.
6] (Optional) Click 'Preview' to preview color selections without making any permanent changes.
NOTE: After the customized color changes have been previewed, 'Preview' becomes dimmed until another customized color is adjusted.
7] Click 'OK'. (The Color Scheme dialog box reappears with the custom scheme color highlighted in the Scheme Colors group.)

8) Do one of the following:

a) Click 'Apply to All' to apply the new standard color to ALL the slides in the presentation.
b) Click 'Apply' to apply the new standard color to the current slide only.
c) Click 'Cancel' to abort the slide color scheme change.