Product Version: NetBeans IDE Dev (Build 200803170003)
Java: 1.6.0_04; Java HotSpot(TM) Client VM 10.0-b19
System: Linux version 2.6.24-12-generic running on i386; UTF-8; en_US (nb)

There is quite an inconvenience in the Properties window when changing a color.

Create a new JFrame form and go to its properties. Find for example the background color property. There should be
something like "[239,235,231]" (with a small color preview). You can now type into this field. You can type any
different rgb values (like "100,0,0" - dark red). But you can also type some named color, for example "red".

When you type "red" in the field, the word "red" is in the field with a color preview (correctly).

But the property field changes from textbox to combobox of type "DropDownList" (C# terminology, sorry). The point is,
that you cannot type in the field anymore, you can just expand the list and choose some color. So if you want to change
the "red" color to "100,0,0" (which is just darker red), you cannot do it without opening a dialog (click "..." button).

The combobox should be of "DropDown" style instead of "DropDownList", so that you can type in the field.

Sorry to annoy you with this link, it is just to explain what I mean:
http://msdn2.microsoft.com/en-us/library/system.windows.forms.comboboxstyle(VS.71).aspx

The user's input should be checked just after the user confirms his input by pressing enter (a dialog "Not a color"
should appear if incorrect color is entered).