Here is a simplfied explanation of how lighting affects costumes it will be the same for puppets.
Light colour affects costume in really very basic ways. Under white light, which contains all the colours of the spectrum, costumes look fine - for example a red dress will look red because there is red light within the white light to be reflected from the dress. If you remove some of the spectrum and turn the stage blue the red dress will turn black because there is no red light for it to reflect. If you add a little red light to a blue stage the dress will look red again.
If under white light you want the red dress to look more vibrant then add some red light and the colours will stand out more.
To do experiments get a small torch (not an L.E.D torch) and a lighting colour swatch book which you can request from a colour manufacturer or pop into your local stage lighting supplier who will give you one.
http://www.leefilters.com/lighting/ 0r http://www.rosco.com/sbreqs/index.cfm
Then turn off the lights and have some fun with colour.
I know this is post is about led technology and I am saying not to use an LED torch but if you use standard theatre lighting then it will be a standard fillament bulb and you will need to use coloured gel to change the colour. With LED you have a red, green and blue colour LED's and by mixing these you can get the different colours below is an image of the lighting colourwheel this will explain what I mean and give an idea as to how RGB Led fixtures work.
Sorry about waffeling on but I know what I mean its hard to explain easily. I am not very good at written explanations.
Standard Lighting - Fillament bulb - yellowish white colour - you will need to change the colour with a filter gel - high power usage - gives out heat - 1 lamp = 1 colour (unless you use a scroller)
LED Light - Red Green Blue Led's - Will produce a bright blueish white - you will need to "mix" the colour you want - low power usage - no heat output- 1 lamp = 26.6 million colour or there abouts.
