Solved Default Paint color palette

[ineuw]

I work almost exclusively with grayscale images and when I use the color palette on the Paint tool (F12), it sometimes displays the enhanced Irfanview palette with predefined colors, and sometimes it shows the standard Windows XP color palette. Is it possible to set the Irfanview palette as the default?

[Mij]

It depends on the color depth of your image. The paint tool (Irfanpaint) never changes the color depth of your image . So if your image is 24bit trucolor then you have a 24bit palette to choose from. If your image is 256 color depth then you can only choose your colors for painting from the existing 256 color palette. Similarly for 16 color depths.
Irfanview does always offer the full 24bit palette but if you choose colors that are not within the existing color range of the image then the color depth is increased to the next level up.

[ineuw]

Irfanview does always offer the full 24bit palette but if you choose colors that are not within the existing color range of the image then the color depth is increased to the next level up.

Many thanks for your reply, Unfortunately, I have not yet used Irfanview for color images, but I did suspect that non-standard shades of grayscale brings up the 256 shade palette (just wasn't sure). On the other hand, I now counted the number of possible grayscale shades and the matrix is 16 x 17, which is 272. What am I missing?

[Mij]

In Irfanview press the I button to see the Current color depth and the Number of unique colors in your image. Assuming you have a 256 color depth you can click on Image >Palette >Edit Palette to see the actual colors which will be in a 16x16 grid. That is what you get if you convert any 24bit image to grayscale using Image >Convert to grayscale.
If you click on the squares of the grid you can see the R,G,B values that they represent. There are only 256 unique grayscale colors ranging from 0,0,0 to 255,255,255 so if you have 272 there must be some duplicates.

I see exactly the same 16x16 grid when I select a color in Paint as is shown in Edit palette from the Irfanview Image menu.