Dimensions in yellow background?

HI I have just spent a lot of time doing my first model of an animal (a shark for a tutorial I am doing).

I made it the right length, but when I reload the file the shark shrinks to a midget version. I noticed that in the Transform property column on the right (press N) that the background is yellow behind the dimensions, which is not normal. I put the shark back how I want it, but it keeps returning to the same size.

I had imported a set of images from the tutorial, but had ended up doing my own shark. I deleted all those images after I had done the shark. I don’t know if the images have anything to do with the problem?

Can anyone tell me how to get rid of this yellow background/ whatever limits the size of the shark object? Thanks

If the value is yellow, that would indicate you have set a keyframe for that setting on the current frame.
You can remove it by RMB on the value and selecting to clear the keyframes