Pixel editor script what am i getting myself into.

Hi PixelFixation​,

you are a coder.

Normally you should know: no feedback is the worst feedback.

Sorry for answering your question quickly and completely.

Hi PixelFixation​,

I think this could do the job (for 16×16 pixel sprite):

// border_singlePixelBorderAroundwithNeighboringPixelColor.jsx
// erstellt einen 1 Pixel breiten umlaufenden Rand mit der Pixelfarbe des benachbarten Pixels
// adding a single pixle of padding around the out side of each sprite the same color as its neighboring pixel.
// 16x16 pixel sprites become 18x18 sprites with a border that matches the next pixel in
// regards pixxxel schubser
var aDoc =app.activeDocument, aSel;
expand (1, 0, AnchorPosition.TOPRIGHT, 1, 2, 16, 0, -1, 0);
expand (1, 0, AnchorPosition.TOPLEFT, 16, 17, 16, 0, 1, 0);
expand (0, 1, AnchorPosition.BOTTOMCENTER, 0, 18, 2, 1, 0, -1);
expand (0, 1, AnchorPosition.TOPCENTER, 0, 18, 16, 17, 0, 1);
function expand (x1, y1, an, l, r, b, t, x2, y2) {
    aDoc.resizeCanvas (UnitValue((aDoc.width.as('px')+x1),"px"), UnitValue((aDoc.height.as('px')+y1),"px"), an );
    aDoc.selection.select([[l,t],[l,b],[r,b],[r,t]], SelectionType.REPLACE, 0, false);
    aSel = aDoc.selection;
    aSel.copy ();
    aDoc.paste();
    aDoc.activeLayer.translate (x2, y2);
    aDoc.activeLayer.merge();
    }

Have fun

I think that can be done with extends riptide, but it will be a bit slow - not as slow as what you're doing. Now. You would just need to create a loop that samples the pixel location you want to copy, the make a selection of the pixels you want to fill.