In this work, we use the spectroscopy-based stellar color regression method with ∼0.7 million common stars between LAMOST DR7 and Gaia EDR3 to acquire color corrections in G − G _RP and G _BP − G _RP. A sub-millimagnitude precision is achieved. Our results demonstrate that improvements in the calibration process of the EDR3 have removed the color term in G _BP − G _RP and eliminated the discontinuity caused by the changes of instrument configurations to a great extent. However, modest systematic trends with G magnitude are still detected. The corresponding color correction terms as a function of G are provided for 9.5 mag < G < 17.5 mag and compared with other determinations. We conclude that the corrections given in this work are particularly suited for cases where the color–color investigations are required, while for color–magnitude investigations other corrections may be better owing to systematics with reddening. Possible applications of our results are discussed.

在这项工作中，我们使用基于光谱的恒星颜色回归方法，在 LAMOST DR7 和 Gaia EDR3 之间使用约 70 万颗常见恒星来获取G − G _RP和G _BP − G _{RP 的}颜色校正。实现了亚毫米级精度。我们的结果表明，EDR3 校准过程的改进在很大程度上消除了G _BP - G _{RP 中}的颜色项，并在很大程度上消除了由仪器配置变化引起的不连续性。然而，仍然检测到G幅度的适度系统趋势。作为函数的相应颜色校正项ģ提供了用于9.5 MAG < ģ <17.5 MAG，并与其他的测定进行比较。我们得出的结论是，这项工作中给出的校正特别适合需要进行颜色-颜色调查的情况，而对于颜色-幅度调查，由于系统性变红，其他校正可能会更好。讨论了我们结果的可能应用。