When looking at images on a monitor screen it's important to know that what's displayed is correct and there are four key-points that can help ensure this which are:
1. Colour Gamut
Check that your monitor can display the correct colour gamut that fits your colour management method. This will be either Adobe RGb or sRGB.
It also helps if you know if your camera shoots in the sRGB colour space or with the broader Adobe RGB.
With Adobe RGB you can shoot emerald-green oceans and brilliant yellow flowers, but if you are using a monitor with a colour gamut not suited to Adobe RGB, the images will not be displayed correctly. On the other hand, while the reproducible colour space for sRGB is narrower, colour management is easier because it is meant for general use. Compacts tend to mostly use sRGB while DSLRs and mirrorless systems are capable of capturing images in both color gamuts.
2. Smooth Gradations
Gradation is used in photo data to display colour shading and to create a sense of depth. A monitor with colour infusion or colour omission issues is unable to display this data correctly and this is why it is important for photographers to use a monitor that is capable of displaying gradations in monochromatic images, including low gradation areas, with no colour infusions or omissions.
3. Even Screen Brightness And Colour
Monitors with poor accuracy or ones whose colour display has changed after long periods of use can have dark patches or sections of colour infusion which leads to nonuniformity which means retouching becomes difficult as the correct colours aren't fully displayed.
When displaying images, it's important to use a monitor that has been adjusted in advance to correct uniformity errors. Some monitors even feature circuitry that takes into account changes in the monitor's displayed brightness etc. that occurs from continued use and adjusts for them.
4. Easy To Adjust Display
Most monitors can be adjusted via buttons found on the front of the monitor or you can use software to do a more accurate job. If you can, use software and a sensor dedicated to the monitor you're using to quicken the process and it often makes it easier too. Remember that making regular readjustments will make it easier to maintain the correct colour display.