If they are text, you should be able to select the Next or Previous buttons and change their font and text colors.
If not, the only way to do it is to edit their original template (a PSD file). And that can be a bit challenging if you don't know what you're doing.
Exactly which Menu Set Template are you using? We can take a look at that, and then give instructions for altering the color, if Text.
Steve and Bill - thanks for the responses.
I am using the Countryside Menu in the Travel set. If I run in "Preview disc", the first screen has both the "Play movie" and "Scene selection" texts in a colour which I selected (different from the default). The problem is that when I move the mouse over whichever one I want to select, the marker (in this case a leaf) displays in the original colour - green - which is hard to see against the menu background (a still from one of the clips).
It's worse when I hit "Select scene" because the menu which then appears, while it has the text "Main menu" in the colour that I want, still has the selection icon (the leaf) in green. This is also true of the (leaf) icon for the next menu screen.
So, is there any way of changing the colour of the leaf????
To change either the "leaf" graphic's color, or that of the Highlight, they would need Photoshop, or Photoshop Elements. Here is a look at that Menu (Main Menu from the Menu Set), with everything turned OFF, but the "Next leaf." I applied a Hue/Saturation Adjustment Layer (not sure that PSE has Adjustment Layers yet - but one could use other methods), linked it to just that Layer, and adjusted the Hue to dark red:
One could do the same, if they wanted to adjust the color of the Sub-picture Highlight. If one were doing this, they would want to record the adjustment for Hue/Saturation, maybe in an Action, to repeat those settings for the "Previous leaf," and the "Main Menu leaf," in this example.
Also, if one were to make such corrections to the Menu Set Templates, I strongly recommend NOT overwriting the existing Templates, but Save_As to that folder. Note that there are necessary naming conventions, and to get a display in the Menu Set Template Gallery, they will need to create a matching PNG.
Since there are many mandatory conventions (Layer and Layer Set naming, PSD file naming, etc.), it would pay to spend some serious time, learning about the structure, before attempting to heavily modify a Menu Set, beyond the customization that PrE allows, within the program.
Next, Photoshp can do Menu Set editing, with no restrictions (other than those mentioned conventions and structure), such as create Layer Sets (translated, when done correctly, to Buttons), but Photoshop Elements can ONLY edit those Layer Sets - NOT create them. Same could be true for features, such as Adjustment Layers. I am just not sure what PSE 11 is now capable of.