Color tuning is a challenge for improving white light LEDs. In this paper, the color tuning in Ba1-xMgSiO4:xEu(2+) (0 <= x <= 0.07) and Ba0.993-yMgSiO4:0.007Eu(2+), ySr(2+) (0 <= y <= 0.07) are investigated. The emission can be tuned by increasing Eu2+ concentration and substitution of the host lattice cation Ba2+ by Sr2+. The emission shows a red shift in Ba1-xMgSiO4:xEu(2+) with the increase of Eu2+ concentration. The red shift results from the preferential occupation of Eu2+. On the contrary, the emission of Ba0.993-yMgSiO4:0.007Eu(2+), ySr(2+) shows a blue shift when partial substitution of Ba2+ by Sr2+. The blue shift is explained by the preferential occupation of Sr2+, crystal field splitting of Eu2+ and the electron binding energy of Eu-O. (C) 2018 Elsevier B.V. All rights reserved.