I've never actually changed the arrows myself, so no guarantees, but try this (the example is for a text area I don't know if it can be applied to a drop down -comboBox-, by the above posts it looks like it can't - it might be worth a try):
First you need to create a CSS(Cascading Style Sheet). Open a regular text document (use notepad for example) and insert this code (modify the colours to suit your needs):
textarea {
scrollbar-base-color: #008000;
scrollbar-arrow-color: #e0e222;
}
Save it as stylefile.css
To load a style file in your webpage use this line in your html code:
<LINK REL="stylesheet" HREF="
TYPE="text/css">
Be sure you upload the CSS file to the correct directory.
The following is a CSS generator (it may be helpful as well):
You should also be able to do this from your html code using the following line of code:
<select style="scrollbar-base-color: #008000; scrollbar-arrow-color: #e0e222;">
**not so sure about this one but give it a try
**For your drop down box in the CSS try replacing the word textaea with combobox