GetCTable
GetCTable Allocate and initialize a new color table data structure
#include <Quickdraw.h> Color QuickDraw
short ctID ; ID of desired color table resource
returns CTabHandle leading to the color table's data structure
GetCTable obtains a new color table data structure and initializes it from
data in the 'clut' resources for that specific ID.
ctID is the identifier of the desired color table resource.
Returns: a CTabHandle leading to the specified resource. If the
resource ID ctID can't be found, the return value is NIL.

Notes: Dispose of any old handles in a PixMap before putting a new CTabHandle
into it. All of your application's 'clut' ID values have to be above 128 and
below 1024. Anything from 0 to 127 has already been reserved.
Values used by your application must be in the ctSeed field in the resource
and Color QuickDraw will put them in the ctSeed field of the color table.
Every other seed value is used to identify new or newly modified color
tables.
Invalidate a modified color table by changing its ctSeed field. Use
GetCTSeed to get a new value for the ctSeed of the changed color table.