Lichess Arrow Colors

Lichess draws the engine's best line in pale blue and every other line in the same pale grey. With three to five lines turned on, you cannot tell which grey arrow is the second best move and which is the fifth. This extension colours each arrow by how good the move is. The best move is green, and arrows shade through yellow and orange to red as the move gets worse. You can see the engine's opinion on the board without reading the list. How the colour is worked out: It uses lichess's own winning-chances curve, the same one lichess uses to decide how to draw the arrows in the first place. It is measured from the point of view of whoever is to move, so the colours mean the same thing for white and for black. A forced mate ranks above any ordinary score. The scale stretches across the moves on the board, so the best move is green and the weakest arrow shown is red. When every move is about equally good, they all stay green rather than being spread out over differences that do not matter. Other things it does: Draws every arrow at the same width. Lichess thins the weaker ones, but the colour already says that, so the widths only added noise. Outlines the arrows so they stay readable over pieces and over light and dark squares. Everything is adjustable on the options page: the colours, the outline, the arrow width, the opacity, and whether the scale stretches per position. There is also a second mode that colours arrows by their rank in the engine list instead, with a fixed palette you can edit. Turn the extension off and lichess's own arrows come back exactly as they were. This is not an official lichess product. It does not give you engine help in games. It only restyles arrows that lichess already draws for you on the analysis board.