Picking up colour pencil from a regular box is a boring and tedious task to make make it more user friendly and convertible is shown below

Supplies

A3 size 4 cardboard sheet
Old book cover hard Bound
Black chartpaper A4 size
Cutter
Measuring Ruller
Geometry Compass
Pencil for marking
Glue for sticking cardboard
And offcourse colour pencils to keep within !

Step 1: Marking of Design on Cardboard Sheet

Take one A3 size cardboard sheet and make similar Design as shown in the figure.
Use compass to make the curvature arc or radius greater than outer lines. Make sure you mark the arc of same size from upward and down as well

Check the number of pencils you want to fit in !!!
Use only one Design to fit 24 shades. I have designed 2 such things in sheet for 48 shades colour pencils

Step 2: Sticking Two Cardboard Sheets

If u have enough thick carboard sheet (approx thickness of 2 sheets of 250 gsm paper)you can ignore this step. I had to do this due to lack of supplies in quarantine period amid Covid 19; pandemic.
Since the cardboard sheet I used is thin (approx 250 gsm ) I am sticking cardboard sheet I drew design with other plain cardboard sheet. Make sure that Design stays on top and not on sticking side

Step 3: Making Strip Based Pencil Holder

Take another sheet of A3 cardboard and cut a strip of less than 2 cm. Make similar marking shown in image and cut the middle "x "looking marks.
Be careful with cutter while using it !!!
Create alternate mountain and valley fold and we are ready for next step

Step 4: Making Slot for Holding Pencils

Before proceeding this step make sure the glued cardboard is stuck properly and has no layer gap in between. While others who used thick cardboard previously can ignore.

Now mark 2 cm thick horizontal line from above and below of marked area.

Split the length into half the numbers of colour pencils you have. If you have 24 shades split the lenght into 12 parts (12above and 12 below)

After each segments are marked keep your set of pencils and mark on alternative side (top and bottom)on cardboard cut 5 mm *2 cm strip for ech colour pencils you have as shown in figure

Step 5: Adding Strip to Slotted Rectangles and Generating Curve Fold

Carefully add strip such that triangles get locked on rectangular slotted holes. Cut the 2 Desi apart and cut locking holes with it as well.With plastic ruller or card opener press it on the curved marking making it fold along curved line and shown in figure

Step 6: Adding Black Stip for Pencil Holding

Cut out black chartpaper strip approx 1.5 cm thick.
Now mark 2 cm curve roughly above and below the curve folded in previous step and also above rectangular slotted holes and make 2 cm vertical cuts in the area where pencil will be placed. Enter the black chartpaper strip and use one pencil thickness and use weaving kind of technique for this also glue up the end parts

Step 7: Making Box for Storing Plates of Colour Pencils

Take next cardboard sheet and make 3 sided 45 degree joints as shown in figure and stick them together
Sticks all the 3 rectangular piece to hard Bound book cover or magazine cover whichever is available