# \#nan

**URL:** https://forum.generic-mapping-tools.org/tag/nan/5.md

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## [How to remove background colour from map](https://forum.generic-mapping-tools.org/t/how-to-remove-background-colour-from-map/5975)

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**Author:** [@VISHU-10-ALT](https://forum.generic-mapping-tools.org/u/VISHU-10-ALT)\
**Replies:** 15\
**Last updated:** [November 5, 2025, 10:05am UTC](https://forum.generic-mapping-tools.org/t/how-to-remove-background-colour-from-map/5975 "2025-11-05T10:05:14Z")

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Hi guys, I’m new to GMT and currently using GMT 6.5 on Linux. I have created one map, but I’m struggling to remove the default background color (gray or any color behind the map). I want the background to be transparent…

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## [NaN Transparency Issues in makecpt Grayscale Plots](https://forum.generic-mapping-tools.org/t/nan-transparency-issues-in-makecpt-grayscale-plots/5835)

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**Author:** [@mbrandin](https://forum.generic-mapping-tools.org/u/mbrandin)\
**Replies:** 5\
**Last updated:** [April 10, 2025, 7:45pm UTC](https://forum.generic-mapping-tools.org/t/nan-transparency-issues-in-makecpt-grayscale-plots/5835 "2025-04-10T19:45:40Z")

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In our lab we have a GMT code that creates grayscale plots that just recently stopped working. Instead of making the NaN values transparent, which it used to do just fine, it instead makes the background bright red. Simp…

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## [Grdimage transparency of NAN values](https://forum.generic-mapping-tools.org/t/grdimage-transparency-of-nan-values/5641)

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**Author:** [@EvanPi](https://forum.generic-mapping-tools.org/u/EvanPi)\
**Replies:** 10\
**Last updated:** [December 16, 2024, 10:28am UTC](https://forum.generic-mapping-tools.org/t/grdimage-transparency-of-nan-values/5641 "2024-12-16T10:28:00Z")

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Hi, I just updated to 6.5 from 6.3, and i find that my grdimage can no longer use the -Q option to plot NAN values as completely transparent if i also have intensity set by -I+d. example: gmt grdimage $filename1 -R$re…

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## [Background color](https://forum.generic-mapping-tools.org/t/background-color/3657)

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**Author:** [@Alzaidy1](https://forum.generic-mapping-tools.org/u/Alzaidy1)\
**Replies:** 10\
**Last updated:** [February 6, 2023, 6:53pm UTC](https://forum.generic-mapping-tools.org/t/background-color/3657 "2023-02-06T18:53:17Z")

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Hello everyone how can I change the background color by gmt