Apparently you can push the chroma extremely far

assets/disk0/tvdos/bin/playtav.js

@@ -498,6 +498,8 @@ let oldBgcol = [BIAS_LIGHTING_MIN, BIAS_LIGHTING_MIN, BIAS_LIGHTING_MIN]
 
 let notifHidden = false
 
+const QLUT = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,66,68,70,72,74,76,78,80,82,84,86,88,90,92,94,96,98,100,102,104,106,108,110,112,114,116,118,120,122,124,126,128,132,136,140,144,148,152,156,160,164,168,172,176,180,184,188,192,196,200,204,208,212,216,220,224,228,232,236,240,244,248,252,256,264,272,280,288,296,304,312,320,328,336,344,352,360,368,376,384,392,400,408,416,424,432,440,448,456,464,472,480,488,496,504,512,528,544,560,576,592,608,624,640,656,672,688,704,720,736,752,768,784,800,816,832,848,864,880,896,912,928,944,960,976,992,1008,1024,1056,1088,1120,1152,1184,1216,1248,1280,1312,1344,1376,1408,1440,1472,1504,1536,1568,1600,1632,1664,1696,1728,1760,1792,1824,1856,1888,1920,1952,1984,2016,2048,2112,2176,2240,2304,2368,2432,2496,2560,2624,2688,2752,2816,2880,2944,3008,3072,3136,3200,3264,3328,3392,3456,3520,3584,3648,3712,3776,3840,3904,3968,4032,4096];
+
 function getRGBfromScr(x, y) {
     let offset = y * WIDTH + x
     let rg = sys.peek(-1048577 - offset)
@@ -723,7 +725,7 @@ try {
                         compressedSize,            // Size of compressed data
                         CURRENT_RGB_ADDR, PREV_RGB_ADDR,  // RGB buffer pointers
                         header.width, header.height,
-                        header.qualityLevel, header.qualityY, header.qualityCo, header.qualityCg,
+                        header.qualityLevel, QLUT[header.qualityY], QLUT[header.qualityCo], QLUT[header.qualityCg],
                         header.channelLayout,      // Channel layout for variable processing
                         trueFrameCount,
                         header.waveletFilter,      // TAV-specific parameter