changing multiple colors

[Hsanon]

Hi, I have a bunch of polylines, in specific layers, and was looking to change colours of some of them. The plines are coplaner and one above the other. coexistant
These are actually floor outlines of a building. 
The pline (floor) colours may range from 100 to 130. and i may like to 

1. insert a colour (floor) at level 108. Hence, all plines which are 108, become 109, 109 become 110... etc till 130 (which becomes 131). There will be no further plines of 108  in that location. a copy of the old lines of 108 can be moved to another location /layer on the drawing for record.

2. Delete a color (floor) at level say, 112. Hence the existing 112 cDrawing1..dwgolor lines can be moved to another location / layer for record, and 113 color plines become 112, 114 color becomes 113, and so on... 130 becomes 129

Since there are so many lines, is it possible to choose them all, ask whether we would like to add or delete a floor, and then do the needful ??? sample drawing attached

[Hsanon]

Apologies.... with trial and error, have made a small program to solve this issue