This Piet Mondrian in wood shows several species in their natural hue; no stain or finish has been applied. With colors like these, you pretty much can't go wrong if you're making decorative boxes. Just let the wood do the talking.
One thing to consider, however, in choosing wood for its color is the long term effect of sun or shade on the color's intensity. These pencil boxes I made a few years ago were very colorful upon completion but over time, the saturation has changed.
Sun can either brighten or darken wood, depending on the species, so the lid of the middle box now looks dark and dull. The underside of the lid, however, still resembles the box when it was first made. Why? Because bloodwood and padauk, woods used in this particular box, darken in sunlight.
The second to last photo is a padauk board that was partially covered by another board in my shop. The part that was getting some sunlight turned dark maroon, while the portion in shade remains orange/brown.
Now, with some wood, it's preferable to keep them in the light. Purpleheart and cherry, for instance. The piece of purpleheart sitting on top in the last photo has been getting plenty of sunlight in my shop while the board below it has been buried in a lumber pile (it's actually brighter than I expected). Purpleheart turns bright purple in sunlight but turns brown in shade. Cherry, as most people know, starts out as a light pink when first milled, but darkens to a rich brown over a relatively short period of time.
So, if you're planning to rely on wood color in your next project, you might want to consider what will happen to its color over time.