Not in a value list such as a drop down or pop-up.
You could display a set of radio buttons or checkboxes and place colored rectangles behind the values.
You could list the values in a portal with containers showing the color in each portal row. You can turn the container field into a button that performs a script that uses set field or other steps to do whatever you want to see happen when the user selects a color.
You could also use Conditional Formatting to alter the b/g color of a field. IOW, if when the value of a target field value is supposed to control what color the b/g becomes, you can use Conditional Formatting to do that.
Look up "Conditional Formatting" here in this forum (or in your Help from the app), to learn more about it.
If the value of target field Type is "Random", and that value of "Random" determines that your fill color should be RED, then go into layout mode, RIGHT CLICK on the field and select Conditional Formatting... there, then in the Conditional Formatting dialog click the Add button, then under Condition set "Value is" and "equal to" and enter Random in the field on the right, then click the Fill Color checkbox and set it to a red color using the color picker. Finally, click OK to leave Conditional Formatting. Go into browse mode and enter "Random" into the value of your target field and the fill color will go red.
I give you this example not because it is perfectly addressing your need, but so that you can quickly see how Conditional Formatting can do what you might need. It is capable of doing a lot more than the simple change I have indicated here.
And in case it is not clear (and it might not be...), you can set up many different fill colors by Adding many different conditions in the Conditional Formatting dialog. IOW, you are not limited to just one condition. That's where the real power lies in Conditional Formatting.
Thanks for your assistance. As an Access and Excel user, I know how to use Conditional Formatting, I just couldn't get it to work. But once I reinstalled 10, it was simple to do. Perhaps 9 doesn't support it or I just wasn't finding it.