THESAURUS
tone down
abate, achromatize, allay, alleviate, assuage, atone, attemper, attune, baffle, bank the fire, blanch, bleach, blunt, chasten, chord, constrain, control, cushion, damp, dampen, de-emphasize, deaden, deafen, decolor, decolorize, dim, diminish, discolor, downplay, drain, drain of color, dull, ease, etiolate, extenuate, fade, fluff, fume, gentle, keep within bounds, knead, laxate, lay, lenify, lessen, lighten, limber, limber up, loosen, mash, massage, mat, mellow, milden, mitigate, moderate, modulate, mollify, muffle, mute, obtund, pale, palliate, peroxide, play down, plump, pulp, put in tune, reduce, reduce the temperature, relax, restrain, shake up, slacken, slow down, smash, smother, sober, sober down, soft-pedal, soften, soften up, squash, stifle, stop, string, subdue, supple, suppress, tame, tarnish, temper, tenderize, tone up, tune, tune down, tune up, underplay, voice, wash out, weaken, whiten
ROGET THESAURUS
tone down
Moderation
VB
be moderate, keep within bounds, keep within compass, sober down, settle down, keep the peace, remit, relent, take in sail, moderate, soften, mitigate, temper, accoy, attemper, contemper, mollify, lenify, dulcify, dull, take off the edge, blunt, obtund, sheathe, subdue, chasten, sober down,
tone down, smooth down, weaken, lessen, check palliate, tranquilize, pacify, assuage, appease, swag, lull, soothe, compose, still, calm, calm down, cool, quiet, hush, quell, sober, pacify, tame, damp, lay, allay, rebate, slacken, smooth, alleviate, rock to sleep, deaden, smooth, throw cold water on, throw a wet blanket over, turn off, slake, curb, tame, smooth over, pour oil on the waves, pour oil on the troubled waters, pour balm into, mattre de l'eau dans son vin, go out like a lamb, roar you as gently as any sucking dove.
Darkness
VB
be dark, darken, obscure, shade, dim,
tone down, lower, overcast, overshadow, eclipse, obfuscate, offuscate, obumbrate, adumbrate, cast into the shade becloud, bedim, bedarken, cast a shade, throw a shade, spread a shade, cast a shadow, cast a gloom, throw a shadow, spread a shadow, cast gloom, throw gloom, spread gloom, extinguish, put out, blow out, snuff out, doubt, turn out the lights, douse the lights, dim the lights, turn off the lights, switch off the lights.
Dimness
VB
be dim, grow dim, flicker, twinkle, glimmer, loom, lower, fade, pale, pale its ineffectual fire, render dim, dim, bedim, obscure, darken,
tone down.
Achromatism
VB
lose color, fade, fly, go, become colorless, turn pale, pale, deprive of color, decolorize, bleach, tarnish, achromatize, blanch, etiolate, wash out,
tone down.