2 problems that I'm looking for a solution to, which are related.

1. We have a new conference room and there is a whiteboard painted onto the wall (approx. 3M x 1.5M). There is a surround around the whiteboard that is deep enough to take a standard LED strip. The electrician tried a normal white LED strip, but it was the wrong shade of white (blue-white) and it faded very quickly, leaving the edge well lit, but the majority of the board dark.

Now I am looking for solution that will light the whole board [b]evenly{/b]. It can be 1 sided or go around all sides, but it need to light the whole board more-or-less evenly. I'm thinking that we need much brighter LEDs and probably from 2 or 4 sides, so that the light is evenly spread - although I'm guessing the middle of the board is going to be either a bit darker or a bit brighter, because the strength of the LEDs will probably be too much or too little to make it 100% even.

2. A 5M long wall needs a fade effect LED. Again, they already have a channel built into the new coving, which was originally fitted, again, with a standard LED strip, but it lit the top 5 - 10cm of the wall and faded out almost immediately. The boss wants something that starts off bright and fades out over 2M - but it must sit flush in the coving and we can't change the coving to accommodate something bigger!

Anyone got any ideas? I'm busy Googling at the moment.

You're inevitably going to have a duller centre than the edges. That's how light works - the closer to the source, the brighter it'll be.
You can get around this by using a diffuser to spread the light more, but then you're going to need vastly brighter LEDs.
I'm guessing your LEDs don't use any form of diffusion and are quite focused.

1 - Backlit whiteboard?

2 - Different paint on the wall?

Yeah, I know that the centre will be duller, but that is irrelevant, I need to give my boss the solution that isn't duller...

1. Backlit whiteboard?

Nope, the whiteboard is painted onto the wall and the wooden surround has been put in place...


2. Different paint on the wall?

The wall has just been painted and must now be lighted.

I've found several bulkier solutions to both problems, but something the size of an LED strip is proving elusive!

This sounds the most sensible option. Is there some kind of translucent material you can fix to the wall and put your LEDs behind?

The other option would, obviously, be some kind of projector/digital whiteboard system.

Ye cannae change the laws of physics man! /scotty

Mount a frosted panel to the wooden surround.
Illuminate from behind with evenly spaced LED strips..
Use dry wipe markers.

Install plaque of thanks to the readers of X404.