不露声色[bù lù shēng sè]
词典not show [betray] one's feelings, intentions, etc.
词典不露声色的意思
词典keep one's countenance：镇定自若；脸不改色；不露声色。
词典not betray one's intention through one's speech and countenance：不露声色。
词典not to show the slightest trace of：不露声色。
不露声色[bù lù shēng sè]
（又作“不动声色”） not show [betray] one's feelings， intentions, etc.; keep one's countenance; not betray one's intention through one's speech and countenance; not to show the slightest trace of (ill-humor); not turn a hair; without letting one's feelings show