# GFCLRLUM System Variable [GstarCAD 2021](Help%20System/GSTARCAD/2021/Index.md) → [System Variables](Help%20System/GSTARCAD/2021/System%20Variables/(System%20Variables).md) → [G](Help%20System/GSTARCAD/2021/System%20Variables/G/(G).md) ## Function Description: The GFCLRLUM system variable is used to control the light level and dark level in single color gradient fill. | | | | --- | --- | | Type | Real | | Saved in | Not saved | | Initial value | 1.0000 | | Range | 0.0 \~ 1.0 | A tint gradient transitions toward white and a shade gradient transition toward black. --- ## Other versions with matching text [GstarCAD 2016](../../../2016/System%20Variables/G/GFCLRLUM%20System%20Variable.md) · [GstarCAD 2017](Help%20System/GSTARCAD/2017/System%20Variables/G/GFCLRLUM%20System%20Variable.md) · [GstarCAD 2018](Help%20System/GSTARCAD/2018/System%20Variables/G/GFCLRLUM%20System%20Variable.md) · [GstarCAD 2019](Help%20System/GSTARCAD/2019/System%20Variables/G/GFCLRLUM%20System%20Variable.md) · [GstarCAD 2020](Help%20System/GSTARCAD/2020/System%20Variables/G/GFCLRLUM%20System%20Variable.md) · [GstarCAD 2022](Help%20System/GSTARCAD/2022/System%20Variables/G/GFCLRLUM%20System%20Variable.md)