Wood color inconsistency

I'm not staining a deck this time, but hoping someone has the answer....

I put one coat of semi-transparent stain on this Elm wood slab I'm making a coffee table top out of. After staining, I noticed some of the circular marks from planing were still there so I decided to just try to sand off a thin layer and restain. However, I had to go a little deeper than planned to get rid of the planing marks, causing one area on the slab to be more of a "whiter" or bare color. I'd hate to sand the entire slab down to get the same consistent color because I'm worried about losing the flatness of the slab. It needs to be level and even all across. So my question is: Will a semi transparent stain even out the color all over? Or will the color still be inconsistent if I leave this as is and just stain again?